peci practicalguide1 0302

O&M Best Practices Series

EnergyManagementSystems

PECI

A Practical Guide

Prepared with funding from the U.S. EPA

October 1997

Acknowledgements

Appreciation is extended to the U.S. Environmental Protection Agencyfor its support of this project. Primary authors were Karl Stum, RogerMosier, and Tudi Haasl of PECI, with contributions by William Pletzof Intel, Beaverton, Oregon. Technical review was provided by thefollowing experts:

Robert BurhennDirector of Physical Plant/Utilities, The CatholicUniversity of America

Kristen HeinemeierSenior Research Engineer, Honeywell Inc.

Terry PetersPresident, National Micro Systems Inc.

Mary Anne PietteStaff Scientist, Lawrence Berkeley National Laboratory

William PletzInstrumentation & Controls Engineer, Intel Inc.

Charlotte Wang, PE, CEMProject Engineer, Capron Company

For additional copies of this guidebook, contact:Portland Energy Conservation Inc. (PECI)921 SW Washington, Suite 312Portland, OR 97205e-mail: [email protected]

Table of Contents

Introduction: An Overview of Computerized Energy ManagementDOCUMENT OVERVIEW ................................................................................................................................................. ii

Chapter 1: Evaluating an Existing Energy Management SystemTHE EVALUATION PROCESS ........................................................................................................................................ 1-2

Evaluating Your Energy Management Requirements ....................................................................................... 1-2Evaluating Your Current Energy Management System ..................................................................................... 1-2System Upgrades—Factors To Consider ............................................................................................................ 1-4Converting a Pneumatic System ....................................................................................................................... 1-4System Replacement—Factors To Consider ....................................................................................................... 1-5

Chapter 2: Specifying and Selecting a New Energy Management SystemProcurement Methods ...................................................................................................................................... 2-1Specification Types ........................................................................................................................................... 2-1

SPECIFICATION DEVELOPMENT AND REVIEW ........................................................................................................... 2-2

A SPECIFICATION CHECKLIST ..................................................................................................................................... 2-3Hardware ........................................................................................................................................................ 2-3Software and Control Capabilities .................................................................................................................... 2-6Installation and Documentation ...................................................................................................................... 2-8Special Considerations for Retrofits ................................................................................................................ 2-10

SELECTING AN EMS PROPOSAL ................................................................................................................................. 2-10

Functionality and Vendor Support Considerations ........................................................................................ 2-10Other Selection Considerations ............................................................................................................................. 2-13

FURTHER RESOURCES ................................................................................................................................................ 2-15

Chapter 3: Commissioning New Energy Management SystemsTHE COMMISSIONING PROCESS ................................................................................................................................. 3-1

Procurement Methods and Commissioning ...................................................................................................... 3-3

ELEMENTS OF A SUCCESSFUL COMMISSIONING PROJECT ........................................................................................ 3-3

Commissioning During Design ........................................................................................................................ 3-4Design Review .................................................................................................................................................. 3-4Design and Operational Intent ........................................................................................................................ 3-5Commissioning Specifications .......................................................................................................................... 3-5Competent Players ............................................................................................................................................ 3-5The Commissioning Plan ................................................................................................................................. 3-7Putting the Plan into Action ............................................................................................................................ 3-7Tips for Managing the Commissioning Authority and Process ......................................................................... 3-9


Chapter 4: Service Contracts for Energy Management SystemsEMS Service Contract Providers ........................................................................................................................ 4-1Various Types of Service Contracts ................................................................................................................... 4-2What To Consider When Selecting a Service Agreement ................................................................................... 4-5

Chapter 5: Strategies for OptimizationBASIC EMS CAPABILITIES .............................................................................................................................................5-2

Scheduling ....................................................................................................................................................... 5-2Setpoints ........................................................................................................................................................... 5-3Alarms ............................................................................................................................................................. 5-4Safeties ............................................................................................................................................................. 5-5Basic Monitoring and Trending ....................................................................................................................... 5-5

PREREQUISITES FOR OPTIMIZING EMS OPERATIONS ............................................................................................... 5-7

EMS Documentation ........................................................................................................................................ 5-8Sequences of Operation .................................................................................................................................... 5-9Current Control Strategies .............................................................................................................................. 5-10Calibration of Equipment............................................................................................................................... 5-10Functional Testing ......................................................................................................................................... 5-11

MOVING BEYOND BASIC ENERGY CONTROL ..........................................................................................................5-13

Energy and Demand Control ......................................................................................................................... 5-13Optimization Example: Savings from Basic EMS ............................................................................................ 5-25Underwriter’s Laboratory Project: Savings from More Advanced EMS Features .............................................. 5-26


Chapter 6: Using EMS for Operational DiagnosticsTrending .......................................................................................................................................................... 6-1Manual Testing ................................................................................................................................................ 6-9


Chapter 7: Non-Energy Control ApplicationsMaintenance Control ....................................................................................................................................... 7-1Remote EMS Operation ..................................................................................................................................... 7-2Security Applications ........................................................................................................................................ 7-3Industrial Applications ..................................................................................................................................... 7-4Retail Applications ........................................................................................................................................... 7-5Miscellaneous Applications .............................................................................................................................. 7-5

Appendix A: Sample Control Specification LanguageQualification of Manufacturer and Lead Installing Technician ......................................................................A-2Trend Logging Capabilities ...............................................................................................................................A-2Extra Monitoring Points, Test Ports and Gages .................................................................................................A-3Partial Sample Performance Specification .......................................................................................................A-4Commissioning and Quality Assurance ...........................................................................................................A-5

Appendix B: Using Spreadsheets for Graphing and Analyzing Trend DataConverting to Spreadsheet Format ...................................................................................................................B-1Opening Data Files ..........................................................................................................................................B-1Setting Up Graphs .............................................................................................................................................B-2Types of Graphs ................................................................................................................................................B-2Scaling .............................................................................................................................................................B-2Multiple Y-Axes ................................................................................................................................................B-3Formatting .......................................................................................................................................................B-3Graphing One Parameter Against Another ......................................................................................................B-3Trends with Different Time-Steps .....................................................................................................................B-4

Appendix CLIST OF ACRONYMS .................................................................................................................................................... C-1

BIBLIOGRAPHY ............................................................................................................................................................ C-2

MATRIX OF RESOURCES .............................................................................................................................................. C-4

The evolution of automatic building control began in the 1880s. Thefirst innovation was a bimetal-based thermostat with a hand-wound

spring-powered motor which controlled space temperature by adjusting adraft damper on a coal-fired furnace or boiler. In 1890, the first pneumatic-powered control became available.

Today automated energy control has become standard practice. Virtuallyall nonresidential buildings have automatic controllers with a computer asthe central processor. These systems are called Energy Management Sys-tems (EMS), Energy Management Control Systems (EMCS), or BuildingAutomation Systems (BAS). Today’s building owners and facility managersmust regularly address the issue of computerized energy management—assessing existing systems, specifying and commissioning new systems,evaluating service contract options, or optimizing EMS operations.

Controls technology is evolving at a rapid pace. Even for recently installedEMS, there are numerous possibilities for system replacements or upgrades:more powerful computers; more zone-level control; more accurate sen-sors; more complex control programs; better service; and other enhance-ments. Continuously advancing technology, combined with the dynamicnature of today’s buildings, makes decisions more complicated for build-ing owners.

Many of the advanced features of EMS are under-utilized. For example,the trending and monitoring capabilities of EMS are powerful tools forimproving heating, ventilation, air-conditioning (HVAC) and lighting andfor reducing energy use, but most facility managers and system operatorssimply do not have the time to fully investigate these resources. Thoseresponsible for EMS upgrade or purchase are not always able to studytheir facility’s exact energy management needs themselves; they may relyon vendors to provide specifications—and they may not receive the opti-mal system for their building. Furthermore, the commissioning process,which can be critical to the success of an EMS, is relatively unknown tomost facility staff.

An Overview of ComputerizedEnergy ManagementToday’s buildings and their potential for enhanced energymanagement

INTRODUCTION

IntendedAudience

This guidebook is intended for

facility managers, owners, or staff

who use energy management

systems, or who take part in

specifying EMS upgrades or new

installations. Commissioning

specialists, engineers, and EMS

vendors may also find it valuable.

ii

INTRODUCTION

Document Overview

This guidebook proceeds in a roughly chronological order covering thelife of an energy management system. More in-depth technical informa-tion is contained in the appendices. The following overview gives asynopsis of each chapter, indicating the topics covered for easy refer-ence.

Chapter 1Evaluating an Existing Energy Management System

For those buildings with an EMS in place, the first step is to evaluate thatsystem and determine if it meets the present and future needs of thebuilding. This chapter discusses the issues to consider when decidingwhether to upgrade or replace an existing EMS.

Chapter 2Specifying and Selecting a New Energy Management System

The first step in a new EMS project is to write the specifications for thesystem. This chapter covers the essentials for writing specifications andselecting the right EMS proposal. (Appendix A provides sample specifi-cations.)

Chapter 3Commissioning New Energy Management Systems

To provide quality assurance, a newly installed EMS should be commis-sioned. This chapter describes the commissioning process and its role ina successful EMS project.

Chapter 4Service Contracts for Energy Management Systems

Service contracts are an essential part of EMS operations. This chaptersurveys the many types of service contracts and providers and lists criti-cal factors to consider when selecting a service agreement.

Chapter 5Strategies for Optimization

This chapter describes methods for getting the most out of an EMS. Pre-requisites for system optimization, including documentation and calibra-tion, are discussed. The basics of EMS operation are covered, along withadvanced strategies for energy and demand control.

EMS manuals focus on the specific equipment installed, rather than thesystem’s potential capabilities. The purpose of this guidebook is to pro-vide easily accessible information and specific “how-to” guidance onchoosing, maintaining, and optimizing the right EMS for your building.

Managing EnergyManagement

For many buildings, the EMS has

more power than any other

equipment to make or break the

operation of the facility. For this

reason, the owner, facility

manager, and system operator

should work together on the

management aspects as well as

the technical aspects of EMS to

optimize cost and energy savings

as well as tenant comfort.

OVERVIEW

iii

Chapter 6Using EMS for Operational Diagnostics

The EMS is a powerful tool for investigating and verifying building opera-tions. This chapter describes diagnostic methods, including trending andmanual testing, that provide valuable information on equipment perfor-mance.

Chapter 7Non-Energy Control Applications

This chapter moves beyond traditional control into discussions of potentialnon-energy tasks in a variety of buildings. Topics include maintenancecontrol, remote EMS operation, and security access control.

Appendix ASample Control Specification Language

This appendix provides sample language for use in specifying control sys-tems, including commissioning specifications and calibration procedures.

Appendix BUsing Spreadsheets for Graphing and Analyzing Trend Data

Trend data are best analyzed using spreadsheet software. This appendixgives details on how to process data from an EMS to a spreadsheet in orderto obtain custom graphics and analysis.

iv

INTRODUCTION

Evaluating an ExistingEnergy Management SystemWhen should an existing EMS be upgraded or replaced?

Some building owners and facility managers have been involved withenergy management systems for years and have established a pattern of

performing periodic system upgrades every few years. Others may havehad only one EMS for a decade and are anticipating a full replacement.Some have in-depth knowledge of the latest technologies; others do not.Regardless of the circumstances, careful consideration should be given tothe following questions:

Energy Management Requirements

• What are the energy management needs of the facility?

• What are the controls requirements to meet those needs?

• Does the existing EMS meet the controls requirements?

Current System Assessment

• What are the full capabilities of the current system? Are those capabili-ties being used appropriately?

• Is the current system technologically obsolete? If not, can the currentsystem be upgraded, or is it an “orphan” system?

• Are problems with the system due to lack of maintenance or service?

• Have the software, firmware, and hardware revisions been kept current?If not, what is the extent of the upgrades required?

• Is the controlled equipment in need of replacement or upgrade?

• Are there an excessive number of trouble or comfort calls for which theEMS is the cause rather than the cure?

When answering these questions, the owner should consider not only cur-rent facility needs for energy management, but predicted future needs aswell. For upgrade or replacement projects, the decisionmaking processshould be systematic and rigorous. This is particularly important when jus-tifying the economics of the choice.

C H A P T E R

The EssentialFirst Step

To design and specify an EMS

that truly meets the needs of your

operation, you must first develop

a clear and comprehensive

understanding of what those

needs are.

1-2

CHAPTER 1

The Evaluation Process

The first step in any EMS upgrade or replacement project is to examineand define your requirements for energy management and controls.

Evaluating Your Energy ManagementRequirements

An evaluation of energy management needs may begin with a technicalassessment (number and type of points required to operate an EMS perthe design requirements, potential control strategies and equipment, etc.)but the building management perspective should also be considered. Thatis, how important is maintainability and comfort to the operation of thefacility? Can control malfunctions and inadequacies be tolerated? Deter-mine your exact requirements for functionality and operations.

An EMS operator’s needs and opportunities are not static. For example,changes in a utility rate structure may offer new energy savings throughload-shedding strategies. In this case, the operator must assess whetherthese strategies would be better accomplished on a new system that makessuch implementation easier. Internal management needs may also change.Some organizations now require more detailed utility usage informationfor accounting purposes to pass along costs or to report energy usage toupper management.

Evaluating Your Current Energy ManagementSystem

In addition to clearly defining a building’s EMS needs, an owner or facilitymanager must also evaluate the state of the current system. Determiningwhether an existing system can and should be upgraded is even morecomplex than the specification of a new system and requires an honestand complete analysis of the current system.

The EMS operator may be the most appropriate person to answer ques-tions and provide insight. If sufficient expertise is not available in-house,consult with a knowledgeable engineer other than the vendor. With thehelp of the system operator, put together a list of negative and positiveaspects of the current system. In addition to a thorough technical evalua-tion, consider other factors, such as ease of operation, required traininglevel of the EMS operator, customer (occupant) comfort and controllabil-ity.

Determine whether the EMS vendor has an upgrade path for the existingEMS. If he does, compare the cost to system replacement and review therelative benefits of an upgrade versus a replacement.

Some further points to consider when evaluating your EMS are:

Get theSystem OperatorInvolved

As the person who operates the

EMS on a daily basis, the system

operator can make a valuable

contribution to an EMS upgrade

or replacement decision. Make

sure he/she has a chance to voice

concerns and ideas about the

performance of the existing

system and features that should

be included in any upgrades or

replacements.

1-3

EVALUATION

1. Is the current system operating to its maximum capability? If not, whynot?

• Are any EMS problems due inadequately trained operating personnel?If this is the case, would replacement of the system solve the problem,or will the same problem exist after the system has been replaced?

• Are problems due to lack of maintenance of the EMS, including soft-ware, firmware, and hardware upgrades?

• Are there a number of points that are being operated in “hand” condi-tion, overridden by the operators, non-operational, or completely by-passed? Why? If so, will upgrading the system really solve theseproblems?

2. Consider these broad management and financial issues: Are there en-ergy management strategies the current system cannot perform? For ex-ample, an EMS may not be able to implement strategies because it cannotinterface with DDC terminal equipment controllers (VAV boxes, fan coilunits, unit ventilators, etc.).

• Has the existing system met your expectations from the time it wasinstalled?

• Have you documented any savings accomplished by the existing sys-tem?

• Will the proposed changes allow greater energy, and/or cost savingsthan the existing EMS system?

3. If the system has been serviced by the vendor (either by contract orcasual labor calls), has the service been up to expectations and have thecosts seemed appropriate? If there is a service contract, is it fully under-stood? Inadequate service could account for poor performance.

4. Do you have one EMS system or several different systems consisting, insome cases, of only one field panel. If there are systems from more thanone manufacturer or separate incompatible systems from one vendor,would both systems be upgraded?

5. Are you preparing to expand the facility or perform major system im-provements that will result in adding points and functions to the existingEMS? Is the existing EMS worth including in these plans? Does it havethe capacity to handle these changes?

6. If a replacement is being considered, do the system components haveany resale value? Some companies purchase the EMS components ofolder systems for sale to facilities still using those systems. Will the ven-dor of the existing EMS offer any kind of trade-in allowance for the oldequipment?

After considering all the relevant factors, the facility manager, with the helpof a consultant or vendor, can begin to formulate options for EMS upgradeor replacement. The development of very detailed options is usually doneby the consultant or vendor, although the facility manager may specify theinclusion of certain features.

1-4

CHAPTER 1

System Upgrades—Factors To Consider

An existing energy management system should be upgraded if:

• It can be upgraded to the current vendor product line.

• It performs the functions the owner thinks necessary.

• The shortcomings of the existing system will be corrected in the up-grade.

If older revisions of software or firmware are being used, “rev up” thesoftware and/or firmware. If the EMS is running on an older PC withoutenough memory or hard-drive storage capacity, replace the PC with themodel the vendor recommends for current operation. Back up the systemsoftware and archives frequently. Store the backups at a location other thanthe EMS control room.

If mechanical system inadequacies or lack of maintenance is partially orfully responsible for perceived EMS shortcomings, those systems should be“tuned up” to improve efficiency and operation. Problems may have arisenbecause the use of the facility area has changed since the initial EMS instal-lation and the EMS was not revised to accommodate those changes.

If neglect or lack of maintenance is a factor, a repair of the system, itscomponents, or its controlled equipment will be required rather than anupgrade. If a service contract will not be purchased, then the system opera-tor and technician will need to be trained to perform the preventive main-tenance and repair functions that a service contract would provide. Mostvendors have advanced training that includes preventive maintenance func-tions.

Converting a Pneumatic System

There are some special considerations when converting an existing pneu-matic system to DDC. Because of the close control of a DDC system, anypoorly functioning equipment will be revealed very quickly by failure tohold temperature, pressure, or humidity within the designated control pa-rameters. Energy waste from leaking or sticking dampers and control valveswill also be revealed. Allow additional funds in your budget to correct theproblems that become apparent.

Converting an existing pneumatic system involves replacing all pneumaticsensors, controllers, and relays. Time clocks are replaced with DDC out-puts; equipment ON/OFF control is wired into the DDC; and the DDC thenenables and disables all equipment, including that under operating controlof any remaining pneumatics. The only pneumatic devices remaining aredamper and valve actuators. These could be operated from an electronic-to-pneumatic transducer or directly from a pneumatic output at the fieldcabinet. A more expensive option is to replace these actuators with elec-tronic actuators, eliminating the transducers entirely.

1-5

EVALUATION

System Replacement—Factors To Consider

In addition to cost, an important issue in system replacement may be therelationship with the vendor of the existing EMS. Vendor issues are often aprimary factor in a decision to replace rather than upgrade. It may be thevendor support, not the system, that is inadequate. If availability of trainingranges from none to very poor, replacement of the EMS and an accompa-nying change of vendor may be in order.

Also consider replacement if:

• The control system is primarily pneumatic.

• The EMS cannot be upgraded to current technology. Changing vendorsshould be considered in this case as the system is considered an “or-phan” system.

• The EMS does not have functions required to implement the desiredtypes of energy management strategies, or it will not interface with VAVboxes that will be upgraded from pneumatic control to DDC control.

• The system is overly complex and arduous to use, so that its features areunder-utilized, or it is one or more software/firmware revisions behind.

• There are significant comfort problems/occupant complaints that a newsystem would resolve. (Note: Be careful not to confuse poor mechanicalsystem design with poor EMS function, e.g., if the use of the area haschanged since the initial installation and the EMS was not revised ac-cordingly.)

• The potential return on investment of the proposed replacement meetscapital project criteria, or utility rebates or local/state/federal tax credits(or rebates) are available.

• Enhanced use of advanced energy management strategies is anticipated.Full use of these advanced capacities can bring a rapid return on invest-ment.

When completing the final analysis, compare the cost per point to replacethe system with the cost per point to upgrade the existing system. If thecosts for replacement are close to what an upgrade would cost, replace thesystem. As a system ages, the service contract costs rise; a new systemwould defer service during the warranty period, and have lower servicecosts than the old system (for the same number of points). These first year’ssavings could be applied toward the new system.

1-6

CHAPTER 1

Specifying and Selectinga New Energy ManagementSystemGeneral guidelines

C H A P T E R

The success of an EMS projects chiefly depends on:

1. Complete specifications—what is wanted, clearly stated

2. Quality hardware and software—what is used to meetthe specifications

3. Competent players—who puts it all together

4. Commissioning—verifying and fine-tuning what was specified

This chapter offers detailed guidelines for tackling the first three elements;the fourth element, commissioning, is discussed in Chapter 3.

Procurement MethodsThere are two possible procurement methods for larger control systems. Inthe traditional approach, called spec and bid, the owner hires a designengineer to design the system and write the specifications, which are thenlet out to bid. In the design-build approach, the owner develops generalperformance specifications which are let out to bid to qualified vendors ornegotiated with a targeted firm. The proposals returned include additionalspecifications. The chosen vendor finishes designing the system and in-stalls it. During the final design process, refined specifications are usuallydeveloped and submitted for approval.

Specification Types

There are three general types of specifications that can be used to start thespecification process: Standard Guide Specification, Proprietary Specifica-tion, and Performance Specification.

Standard Guide Specifications are available from many agencies andgroups. Standard industry specifications provide a “generic” form of con-trol specifications. Other companies and large owners such as state andlocal governments have developed their own sets of control guide specifi-cations. Even vendors can provide a generic specification. Sources for speci-fication guides are listed at the end of this chapter. These are a good placeto start.

A Noteof Caution:

Design-build projects tend to have

less detailed specifications, which

may lead to reduced quality and

difficult enforcement.

2-2

CHAPTER 2

Proprietary Specifications are specifications from vendors that state thebrand and model number of the products being specified, sometimes add-ing the phrase “or equal approved by. . .” These specifications may limitcompetition and lead to higher costs. However, for critical applications,you may want to do just that to get the system or vendor you really need.

Performance Specifications describe the control device generically, list-ing its intended function and necessary characteristics. A problem withperformance specifications is that bidders often supply the lowest priceand/or quality product that meets the specification. On the other hand,detailed specifications may require more design budget and time than isavailable and may limit creativity on the part of the bidding vendors. Re-quiring detailed specifications for hardware also means that the controlsdesigner/spec writer must be well qualified in the field. Very detailed speci-fications must be accompanied by commensurate detail on the performanceof those components if the design intent and the real needs of the ownerare to be met.

Obtaining a balance between component specificity and performance lan-guage in control specifications can be difficult. One solution is to developa specification that combines the best characteristics of the three typesdescribed above. Such a specification would include:

• A detailed written design intent narrative for each system, including thepurpose of the system.

• Measurable performance criteria (“shall maintain duct static pressureduring normal operation [except during startup] of within +/- 0.2 inchesfrom the setpoint”). Refer to Appendix A for a sample of part of a perfor-mance specification.

• Detailed specifications as to what equipment is to be supplied, withdetailed component descriptions and specifications in as many areas asthe owner and specifier feel comfortable. (Note: When upgrading orrenovating an existing system, very detailed specifications of manufac-turers, model numbers, ranges, etc., are warranted in order to keep thenew components compatible with existing equipment and O&M proce-dures.)

• A clause requiring the vendor to meet both the design intent and perfor-mance specification, as well as the detailed specifications. Where thereis a conflict, the vendor is required to meet the performance specifica-tion with an approved alternate component.

Specification Developmentand ReviewIt is wise to obtain at least two sets of specifications as reference guidesbefore proceeding with a vendor or a specification writer: one from anowner representing the owner’s point of view; and one from a controlsvendor providing good detail on component specifications. Read througheach of them and make notes about your system’s needs as well as a list of

BuyerBeware

Before assuming that vendor

specs are truly generic, find

out if there is anything in

the specification that only

that company can provide.

2-3

SPECIFICATIONS

questions and issues needing clarification.

Candidates for developing the specification include controls vendors, con-sulting engineers, or in-house staff. Make sure to select a qualified personfor this important job, one who will produce specifications that are custom-ized to the project in question, not just an edited version of the last project.Often, local control vendors will offer to write a control specification inorder to develop a working relationship with you. Take advantage of theirexpertise, but make sure they do not inappropriately limit competition.

If the project is a negotiated proposal with a single vendor, the specifica-tions may be less detailed than a job going out for bid. However, even ifyou have full confidence in the vendor, you should still screen and approvetheir programmer and site technician.

A commissioning consultant, involved during development of specifica-tions and design of the system, can provide an unbiased expert technicalreview in your interest and help ensure that the specifications contain ad-equate quality assurance procedures. (Refer to Chapter 3: CommissioningNew Energy Management Systems, for details.)

In all cases, the facility manager or owner should assist in a significant way:becoming involved early on with developing design intent and performancecriteria; consulting the designer or vendor if questions arise; and, if answersare unsatisfactory, calling another vendor for a second opinion. The speci-fications should be completely reviewed prior to the final draft. If the facil-ity staff reviews the design and specifications before they are let out tobid—ideally as an integral part of the design team—there will be fewerchange orders. Items such as additional monitored points, control strate-gies, and user interface features, if added later, will cost considerably morethan if they had been included in the original specifications.

A Specification ChecklistThis section lists items that should be covered in the control specification.Some items refer to actual specification language provided in Appendix A.This is not a technical or exhaustive discussion of control specifications,but a practical guide for the working facility manager or systems operator.

Hardware

Expandability. Specifying the wrong model or brand can limit future op-tions. A less flexible model or brand may not allow: 1) upgrades to newsoftware versions or programs, without the purchase of expensive hard-ware; 2) upgrading to the next “higher” model, without changing the entirefront end and some panel hardware; 3) expanding the system to coverneeded points for renovations or additions.

Specify any potential upgrades to the system, both the number of pointsand controllers in each cabinet and software enhancement compatibility.

2-4

CHAPTER 2

Make sure you clearly understand the upgrade limitations and opportuni-ties of the system. Specify any features that will be included in the systemcapabilities, but not set up. Vendors may offer a basic control system soft-ware package with a number of optional modules. Without these modules,the package may not function as hoped. For example, the ability to cus-tomize your own system graphic schematics or to view trend graphs onscreenmay require software modules not included in the basic package, althoughthe specifications say the system is “capable of” these functions (i.e., thesystem is capable if you have the right modules).

Interfaces with Other Equipment and Controls. A frequent source ofproblems is the interface of the EMS with equipment that has some standalonecontrols. Clearly specify the responsibility of all parties regarding the setup,control, and testing of equipment that has some integral controls but willbe interfaced with the EMS. Delineate the respective responsibilities of thecontrols contractor and the equipment contractor for specific functions andsequences. State clearly:

• What is being controlled.

• What is being monitored.

• What is just being enabled.

• Who is providing the wiring and tubing between equipment andcontrollers.

• Who is providing the equipment and controllers, valves, dampers,actuators and sensors.

• Who is providing the programming.

Interoperability—BACnet. Specifying that systems or components beBACnet-compatible is highly advocated. However, the words “BACnet-com-patible” only mean the equipment controllers have the potential capacity tocommunicate with each other. It does not mean that the interface will beeasy or automatic—significant and sometimes problematic adaptation maybe required. LonWorks is another protocol that many manufacturers use. Itworks well for equipment that is compatible with its protocols. The futureis likely to be dominated by BACnet controllers. Your main concern shouldbe to specify compatibility with systems likely to be added to the facility inthe near future.

For equipment that must communicate with other brands or equipmenttypes, state the requirements precisely and specify that it be set up andoperable. Specify that the gateway for communication between desiredequipment will be provided and made functional. Specify the subcontrac-tor who is responsible, if known.

CPU and Monitor. Software and graphics require increasing amounts ofcomputer resources and speed, making it difficult to plan ahead accurately.For systems with color graphics, specify CPU speed, cache, memory, etc.,to be at least equal to that of the current typical upper-end personal com-puter. (This may require some forethought in projects with a timeline of ayear or more.) Similarly, specify a terminal that will not be obsolete before

InterfacingControls withPackagedEquipment

If requirements for interface of

the central EMS with packaged

equipment are not clearly stated,

the controls vendor or the

equipment subcontractor may not

include the interface work in

their bids, resulting in contract

problems and less than optimal

control of the equipment.

2-5

SPECIFICATIONS

it’s installed. Current public-sector purchasing is a good benchmark.

Also, if programming must be accomplished with the workstation off-line,consider specifying another workstation. Specify any accessories needed,such as modems, serial ports, etc. Some facility managers have found it moreeconomical to purchase the CPU and monitor themselves, using the configu-ration specified by the vendor.

Distributed Panels. To increase flexibility for future change and expansion,require that panels where any changes or additions might be made use uni-versal input/outputs (I/O). This allows for each input or output to be soft-ware-assigned as either digital or analog. Or require that the panel be modular,with the capability of receiving digital or analog modules anywhere in thepanel. Specify that each controller panel have a permanent label affixed withits control drawing ID; also include descriptive, non-numerical names thatsuccinctly identify the systems being controlled in the panel.

Make sure the software/hardware system has auto-build network features.This allows the configuring of a new point in one panel to be automaticallyrecognized and usable by all other panels, greatly reducing the time it takesto make changes in the system.

Field panels should also operate in a “standalone” mode during a communi-cations break with the central terminal. For larger facilities, a desirable fea-ture is the ability to access the entire system by plugging a laptop PC intoany field panel.

Network Criteria. Gain an understanding of the how the CPU and networkconfiguration options and features will affect speed (the rate at which panelsshare information). This will determine how quickly information (tempera-tures, status, etc.) fill the graphic schematics, how fast point displays scrollon the screen, how long it takes to back up the system, etc.

Printers and Portables. If specification of printers and portable terminals(laptops or handheld keypad units for servicing) is delayed, it may not bedone at all. Specify at the beginning that the printer for handling alarms aswell as the graphics, or color, printer for trend graphs, etc., be provided andhooked up. Include any desired laptop or portable handheld diagnostic orcontroller setup terminals.

Sensors. Sufficient sensor accuracy is necessary to minimize unnecessaryhardware costs and ensure proper system control. For example, general con-trol of chilled water supply and monitoring the return may need a tempera-ture sensor accuracy of +/- 0.3ºF to 0.5ºF. However, if the chilled watersupply and return is being used for energy consumption calculations in aperformance contract or for billing purposes in a purchased chilled waterarrangement, sensor accuracy may need to be significantly better. In thosecases, the sensors should also be calibrated to within 0.1ºF of each other. Fora sample of recommended sensor accuracy values, refer to the Calibration sec-tion of Appendix A: Sample Control Specification Language. Sensors should alsohave their range specified as well as any special operating conditions (out-doors, within a caustic exhaust fan, etc.).

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CHAPTER 2

Valves and Actuators. Specifying the right valve and actuator is importantto ensure optimal system control without unnecessary modulation or hunt-ing. Valves must be sized correctly; in some cases, a pair of valves in seriesmay be necessary to provide the proper turndown ratio for tight control.Valves must also be able to provide tight close-off against worst-case sys-tem-head pressures. Question the vendor on these issues.

Dampers. Specify the tightness and leakage rate of dampers appropriatefor the application, as well as blade and edge seals for most applicationsand special support shafts for large dampers, if necessary. Be specific.

Monitored Points. To assist in commissioning and for improved controland troubleshooting of the system, additional monitored points may be neededbeyond the minimum necessary to control the building to the specified se-quences. Confer with the commissioning consultant and determine whatadditional points should be added to the specifications.

Test Ports. Newer EMS designs tend to omit many test ports because datacan be read from an EMS readout. However, such ports can be valuable forcalibrating and checking EMS sensor accuracy. Make sure that sufficient testports for handheld instrument readings are provided near all piping systemsensors at the primary system level to aid in calibrating control points and incommissioning and operating the systems. Also, consider test ports for trouble-shooting in strategic locations where sensors or gages are not planned. Con-fer with the commissioning consultant to determine these port locations.

Gages. Ensure that gages are provided in the following locations, even if asensor is included as a point in the control system: 1) pressure gages onboth sides of all pumps greater than 1 hp; 2) mercury thermometers in thereturn and supply of all primary thermal plant equipment (chillers, coolingtowers, boilers, converters, etc.). Gages are often provided by the mechani-cal contractor, but retrofits may require the controls vendor to supply them.

Offsite Communications. Specify who will have modem access to the siteterminal and what the level of access will be. It is generally advisable to givethe vendor access to the system to simplify service and troubleshooting.Clearly state any software setup that the contractor should perform at anyother sites. Specify what alarms and warnings will occur offsite and specifyauto-dial/auto-answer features and setup. Specify clearly any tie-in require-ments to other facilities’ EMS via modem, dedicated line, or the Internet.

Software and Control Capabilities

User Interface and Graphics. For larger systems (buildings over 50,000square feet), make sure the EMS program runs in a WindowsTM or UnixTM

environment and that the system is menu-driven.

The controls vendor’s idea of “schematic graphics” may be different fromyours. Review options and levels of detail with the vendor before specify-ing. If desired, specify that the contractor complete all schematic setup dis-plays, including where applicable: status of monitored and controlled ON/OFF points; current analog input; current setpoint and DDC output; identifi-

2-7

SPECIFICATIONS

cation for each point; state of each control loop and equipment (auto,manual, normal, alarm); point alarm lockout status; symbolic graphic ofequipment; and online directory of schematics.

Compare among systems, and specify as needed, the nested or layeredlinkages that will be set up for facility mapping and navigation. In somesystems, users can click on an onscreen facility map to bring up a floorplan that displays zone temperature information and the serving HVACsystem schematic. Some systems even allow current temperatures in zonesto be represented by different colors for quick floor assessment. Specifyhow much mapping and linking will be done and the graphic representa-tions to be provided.

User Access to Programming. Clearly specify the accessibility of the dif-ferent types of programming to which staff will have access to upon instal-lation (not as an add-on later). Determine if facility staff can access setpoints,reset schedules, deadbands, sensor and actuator calibration adjustments,controller setup screens, loop-tuning parameters, graphical programmingscreens and inputs, line programming portions of the system, override sched-ules, override values, etc.

If facility staff plans to do custom programming or editing, the actual pro-gramming code of a few vendors should be viewed and compared for“user-friendliness.” Some EMS have features that allow the user to stepthrough a program sequence electronically, simulating the sequence, to aidin testing and debugging the sequence before it is online. Consider thisfeature.

Compare the relative ease among systems of adding and modifying graph-ics to the schematics and inserting point display information. Specify ac-cordingly.

Trending. Often the more powerful trending features are not included in avendor’s base package. Consider specifying comprehensive trending capa-bilities to aid in system operation, troubleshooting, and commissioning.Clearly specify the trending capabilities of the system. Refer to Appendix Afor a sample specification of trending features.

Alarms and Warnings. Specify that the EMS should have multiple levelsof alarm designations, each with options for annunciation and reporting,including offsite reporting, (monitoring sites, pagers, etc.). Specify whichwill be set up by the vendor and which by facility staff.

Reports. Specify that the system will be set up to generate automaticallythe following types of reports: general listing of all points; all points inalarm, overridden, disabled or locked-out status; DDC controller trend over-flow warning; history of equipment ON/OFF commands and status andreason for the command; weekly schedules and holiday program; limitsand deadbands.

Security. Specify the levels of security access to the system to be providedand set up.

A Noteof Caution:

Access to the code may be very

valuable to the facility staff

member who has the technical

interest, skill and time to use it

properly; but improper use by

insufficiently skilled staff may

cause corrupted code and

malfunctioning systems.

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CHAPTER 2

Control Strategies. All too often, EMS power and flexibility are under-utilized, particularly if the desired control strategies are not explicitly listedin the specifications. List every energy-conserving, demand-limiting, andcomfort-related control strategy to be included in the system. Do not use oraccept “the system shall be capable of” phrase: State that the strategy willbe programmed, set up, tested, and fully functional. Refer to Table 5-1,Selected Energy-Conserving Control Strategies, for a list and description ofrepresentative strategies. To take full advantage of the power in a newEMS, specify as many of these strategies as possible and affordable.

Enhanced ControlStrategy SavingsCan JustifyUpgrades

When specifying a new control

system, significant energy bill

savings can be realized by

investing additional design time

to incorporate all feasible energy

and demand saving strategies.

The projection of these savings

can be used to justify upgrading

an existing system or purchasing

a new controls system.

The graph on the right illustrates

an actual example of a 60,000

square foot commercial building’s

savings from incorporating a new

EMS system with improved

strategies for minimizing

resistance heat.

Installation and Documentation

Vendor and Staff Qualifications. The success of a controls project de-pends more on the individuals hired to design and install the system thanon the hardware and software chosen. In the project specifications, it isimportant to require approval of the qualifications of the company, thelead programmer, and the lead installing technician. Even if a designatedcompany is to be used, the staff qualification requirements are important.Most companies have a range of skill on staff and, without a written re-quest or specification, there is no guarantee that higher-level staff will beassigned to your project rather than someone marginal or even incompe-tent. (A sample specification is provided in Appendix A.)

Sequences of Operation. One of the keys to a successful EMS installationis the clarity and completeness of the written operation sequences. Ideally,the full operation sequences for each piece of equipment should be in theoriginal job specifications. If the designer’s specification are not detailed

0

20

40

60

80

100

120

140

160

180

200

0 0.5 1 1.5 2

Heating Degree Days (thousands)

kWh

(thou

sand

s)

kWhBefore

kWhAfter

FIGURE 2.1.Resistance Heat Energy Savings Through EMS

2-9

SPECIFICATIONS

and explicit enough, significant interpretation is required of the controlsprogrammer, who may not have the expertise and certainly will not knowthe designer’s full intent for each control loop. To prevent this, encouragethe designer to provide extra-detailed sequences and have the facility tech-nical staff review them for clarity. Involving a commissioning consultantduring design will also ensure that the sequences are sufficiently detailed.(Refer to Appendix A for a specification regarding sequences of operation.)

Submittals. Submittals requiring approval of all control equipment prior toinstallation are valuable for early identification of areas needing to bechanged. A detailed review of the control drawings at this stage can iden-tify control points, sequences of operation, schematics, etc., that are incor-rect, unclear or need to be changed.

Commissioning. Commissioning, a systematic quality assurance and qualitycontrol process, can reduce problems at turnover. Include detailed com-missioning requirements in the specifications. Refer to Chapter 3: Commis-sioning New Energy Management Systems, for further details, and to thesample specifications in Appendix A. The specification language in theappendix can be adapted to project specifications by a qualified commis-sioning consultant.

Completion Milestones. After substantial completion of a project (whenthe owner can take useful occupancy of the system) the contractor maylose interest in the full completion of his tasks. To avoid frustrating delays,add a milestone to the specifications: functional completion (the point whenall remaining test, adjust and balance (TAB) and commissioning responsi-bilities of the contractor are complete, except for seasonal or deferred test-ing.) For example, functional completion could be specified as 60 daysafter substantial completion, with a monetary penalty for default.

O&M Manuals. The completeness and accessibility of the O&M documen-tation is critical to the ongoing use of an EMS. Often the documentationcontains non-applicable information and is all in one binder without divid-ers or even a table of contents. In the specifications, provide detailed re-quirements for O&M manuals. Refer to Appendix A for a sample specification.

As-Built Drawings and Documentation. Controls contractors often de-velop as-builts early to obtain payment at substantial completion before thesystem is fully debugged and while sequences and parameters are stillchanging. As-builts should include complete point data for each point inthe system, including “virtual” points, and a fully commented copy of eachDDC panel operating program. It is best to require that the updated as-builts be submitted after all commissioning testing is complete.

Training. Key to the full utilization of an EMS is the training of facility staff.Too often, this important aspect of a project is inadequate in duration,planning, or content. Provide detailed requirements in the specificationregarding operator training. A sample specification is found in Appendix A.

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CHAPTER 2

Warranty. Consider specifying a warranty of three years for all controlequipment, analog sensors, and I/O modules, and a warranty of one yearfrom acceptance for all other materials, installation, and workmanship. Beclear in the warranty about electrical components that are related to or partof the controls installation, which may otherwise not be included in thewarranty.

Support. If a maintenance contract or onsite assistance during the first fewmonths or year will be part of the original job specifications, make sure alldetails are clear. Include the response time for emergency service calls andspecify whether after-hours visits and regular phone support are provided.State that the supplier shall have an in-place support facility within 150miles of the site with technical staff, spare parts inventory, and all neces-sary test and diagnostic equipment.

Special Considerations for Retrofits• Make sure that the specifications state that the contractor has viewed the

site to his satisfaction and has an understanding of current site and equip-ment conditions.

• Clearly state for each piece of existing (and any new) equipment howthe equipment will be controlled, how the equipment interfaces withthe new controls system, and who will make that interface. Clearly stateany responsibilities of other vendors.

• For each piece of equipment, identify what troubleshooting, if any, willbe completed by the contractor on existing equipment, hardware, orsoftware that is found to be malfunctioning.

• Specify that when connecting to existing pneumatic valve and damperactuators, the following shall be verified: spring ranges; good conditionof diaphragms; and good condition of all linkages, bushing, packing,stems, valve seats, etc.

Selecting an EMS Proposal

Making a good final selection requires learning as much about the prospec-tive EMS as if you already owned it. In some cases, price will be the fore-most consideration, but many other technical, financial, and vendorconsiderations are important. A proposal-ranking scheme may help sortout all these complexities, so that bids can be evaluated not only on lowestprice, but also on value, as determined by examining the costs and benefitsof each proposal.

Functionality and Vendor Support ConsiderationsAs a first step in evaluating bids, consider the following factors:

Vendor Qualifications• Experience and background levels of personnel in charge of user training.

Connecting to andTesting ExistingEquipment andControllers

When a new control system is

installed in an existing building,

the specifications should carefully

detail how much troubleshooting

will be provided by the controls

vendor in integrating the new

controls with old equipment.

Likewise, testing requirements

should be clearly stated for

control sequences of equipment

that is partially controlled by the

new system and partially by

existing standalone controllers.

ProprietaryFeatures

The complex and proprietary

nature of some systems results in

a restriction of features and

control for the building operator.

Make sure that the new specified

system will offer at least as much

control to the operator as the

system being replaced.

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SPECIFICATIONS

Clarity and user-friendliness of the manufacturer’s operator manuals andas-built documentation.

• Response time to repair problems, stocking practices for repair parts,and the skill required to make replacements.

• Type of service contracts available (see Chapter 4: Service Contracts forEnergy Management Systems).

• Manufacturer and/or vendor experience in installing and servicing anEMS for the particular application.

• Qualifications of lead programmer and onsite installing technician (seeAppendix A: Sample Control Specification Language).

• Availability of local technical and service support.

• Vendor reputation for timely project completion.

• Field training capability.

• Availability of expanded training in classroom (offsite) environment.

• Vendor willingness to enter into long-term pricing agreement.

• Vendor’s past history of avoiding production of “orphan” systems (i.e.,systems that cannot be upgraded without replacement of major portionsof the system).

• Commissioning and installation quality control features.

Hardware• Capability to expand in order to control additional systems, buildings,

and modifications to the original EMS.

• Use of two-wire communications cable.

• Use of standard sensor hardware.

• User-friendly operating system and graphics.

• Use of DDC-type field panels.

• Use of field panels that interface with terminal or PC.

• Software that will be compatible with revisions or upgrades.

• Terminal controllers with proportional/integral/derivative (PID) control.

• Field DDC panels with PID control.

• Field DDC panels with automatic loop tuning.

• Terminal controllers with the capacity to have their points unbundled.

• Standard operating environment (MS-DOS, Windows, UNIX, etc., as ap-propriate).

• Method of sensor calibration that follows an industry standard (4-20 mA,0-5 or 0-10 vDC, thermistor, etc.).

Functionality• System ability to get back online automatically after power is restored.

• Number of password-controlled levels of access.

• Central computer’s capability to integrate DDC, energy management,and lighting control, as well as fire and security/access and facility man-agement programs.

• Compatibility with existing EMS hardware.

2-12

CHAPTER 2

• Ability to communicate with other competitive systems.

• Compatibility with existing local area computer networks and ability toutilize those networks for energy management.

• Use of standard personal computer front end.

• User access to information from the network at the field panel.

• User access to point data at the field panel level.

• User access to programming at the field panel level.

• English language readouts at the field panel level (not coded).

• Field panel information available by menu prompt.

• Field panels that can operate in “standalone” mode in the event of acommunications loss.

• Ability to tie into other facilities via modem, dedicated line, or the Internet.

• Adequate trending features (see Appendix A: Sample Control Specifica-tion Language).

• Trend data exportable to spreadsheet or database software.

• Automatic system diagnostic features.

• Standard auto-dial/auto-answer modems.

• Alarm functions that can initiate auto-dial to remote computer.

• One programming language for entire system.

• Programming language that is simple and accessible.

• Dynamic graphics with real-time point values.

• Comprehensive online help with a search function.

• Simple method of graphics generation.

• CAD or scanned graphics import capability.

• Terminal controllers that interface at controller thermostat for PC or ter-minal.

• Adequate number of control strategies.

Cost Considerations

• Costs and time required to alter the EMS database and/or software.

• Costs of adding points after the EMS is installed. User-friendliness inadding and deleting points and changing the software. Ability to per-form these changes without shutting down the system.

• Overall cost per hardware point (if this varies significantly from bid tobid, find out why).

• Total number of hardware points and software points.

• Total number of monitoring-only points not needed for sequence con-trol.

• Software costs included in bid or as extras.

2-13

SPECIFICATIONS

Other Selection Considerations

Number of Vendors. It is advisable to narrow the list of vendors to thosethat are appropriate prior to performing a formal evaluation. Some systemsmay be too small for your application, or the potential vendor may be toofar from your facility.

Facility References. To help decide on a vendor, contact similar facilitieswhere the vendors under consideration have completed projects that havebeen operational for at least a year. (Have the vendor provide a referencelist with facility manager names and telephone numbers.) Discuss the sys-tem with the facility manager and system operators; find out whether theyare satisfied with the system, service, installation, and competence of ser-vice personnel. A site visit and system demonstration would be most ben-eficial. Have the owner’s primary system operator attend the systemdemonstration and discuss the system with the operator at the site. Try tomake the site visit without the vendor’s representative so that the demon-stration will be performed by the building operators and they can speakfreely about the system and any shortcomings it may have.

Vendor Support. A vendor in close proximity to the facility has the advan-tages of faster response time and lower service response costs. Make surethe local vendor has full service capabilities and isn’t relying on technicalassistance from a distant branch, regional, or main office. Determine thevendor’s level of customer support by telephone. If a new system is to beinstalled, see if the vendor can access the EMS from his service office toassist with problems or troubleshooting—at least until the operator is fullytrained on the system. Find out if the vendor has 24-hour emergency ser-vice and determine the standard response times. If the vendor is local andhas an onsite training facility, training will be more convenient. (It is gener-ally desirable to receive training away from your facility to allow you toconcentrate without distractions.)

Vendor Staff Qualifications. Concern about the brand of the EMS canovershadow the importance of the contractor’s role in the project. Thevendor’s delivery team will often have a greater impact on the project’soutcome than the equipment itself. For this reason, facility managers shouldconduct thorough interviews, inspections of previous job sites, conversa-tions with references, and visits to potential vendor’s offices. Even if youare already committed to a vendor, it is a good idea to contact other ven-dors to obtain a second or third opinion about how best to upgrade yoursystem and meet your energy management needs. This helps keep thevendors competitive. Refer to the Qualifications section of Appendix A foradditional details.

Long-Term Financial Considerations. Real-world decisions about EMSprojects are often driven by available funds, budget cycles, and expectedreturns on investment. The following guidelines take into account not onlythe obvious initial costs of the system, but also less obvious future financialimpacts:

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CHAPTER 2

1. If the system is not competitively bid and a “captive” vendor is chosen, thevendor should be willing to enter into a pricing agreement that wouldallow a guaranteed pricing structure. Maintenance costs, replacement partcosts, software and hardware upgrade costs, and operator training costsneed to be taken into consideration along with initial purchase price. Along-term pricing agreement may extend up to five years.

2. It is in your best financial interest to have the least possible dependence ona vendor for maintenance, operations, programming, graphics, databaseconstruction, and even installation. This translates to a simple program-ming language/system, ease of graphics generation by the operator, andease of operation of the main system.

3. The system should have no proprietary sensors. The fewer proprietarycomponents required, the more components can be purchased in a com-petitive market at lower costs.

4. All systems require operator training. The more complex the programminglanguage, the higher the cost—not just training costs, but operations andmaintenance costs as well.

5. A system that does not require the vendor to make programming changeswill most likely incur lower long-term costs than programs/databases thatare “burned” into an EPROM (Electronic Programmable Read Only Memory)that is installed in the field cabinet. Hard-coded programs will mean moredependence on the vendor, resulting in higher service/maintenance costs.

6. The capability to make operational changes (programming and databasechanges) to mechanical systems at the operator level is highly desirable.This also leads to easier implementation of energy management strategies.

7. To ensure that interfaces with upgrades in hardware and equipment in thefuture are reasonably possible, the vendor should be actively working onbecoming completely BACnet-compatible. Ask about vendor commitmentto interoperability and BACnet. “Adapting” is the wrong answer—they shouldbe “adopting” the standard.

Attribute A(e.g., graphics capabilities)

Attribute B(e.g., interoperability)

Attribute C(e.g., standard sensors)

Attribute D(e.g., sensor accuracy)

Proposal A Proposal B Proposal CScale

0-5

0-5

0-10

0-10

5

3

4

8

4

2

5

10 7

7

4

1

Total 20 21 190-30

FIGURE 2-2.Sample Evaluation Matrix

Using anEvaluation Matrix

The owner and facility manager

draw up a list of the system

features and capabilities that are

considered important to their

application. These items are

assigned weighting factors to

indicate their relative importance.

Each bid is then evaluated against

each list item, perhaps on a scale of

1 to 10. The bid proposal that

scores the highest is considered to

be the best choice from a technical

perspective.

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SPECIFICATIONS

Further Resources

American Society of Heating, Refrigeration, and Air-conditioning Engineers(800/527-4723), “Automatic Control,” ASHRAE Applications, 1995

British Columbia Buildings Corporation, BCBC Comfort Control SystemManual (download at http://highrise.bcbc.gov.bc.ca/ccs)

Cratty and Williams, “Energy Management Control Systems,” from EnergyManagement Handbook, The Fairmont Press (770/925-9558), 1992

Gupton, G., HVAC Controls: Operation and Maintenance, The FairmontPress (770/925-9558), 1996

McGowan, J., Direct Digital Controls: a Guide to Building Automation, TheFairmont Press (770/925-9558), 1995

Portland Energy Conservation Inc. (PECI) and U.S. Department of Energy,Model Commissioning Plan and Guide Specifications, 1997(download at http://www.teleport.com/~peci)

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CHAPTER 2

C H A P T E R

Today’s buildings and their internal systems have become increasinglycomplex. The design and construction disciplines have become frag-

mented and specialized. Yet low-bid policies are still the norm. More thanever before, energy management systems need a comprehensive, system-atic quality assurance process.

Ideally, the commissioning process starts in the design phase and contin-ues through the construction phase and the warranty period. It providesdocumentation of design intent and verification of equipment performance.Commissioning also verifies that complete and accessible equipment docu-mentation remains onsite and that facility staff is adequately trained tooperate the EMS.

In this chapter, we look at the commissioning process as it relates to con-trol systems, providing an overview of the process, tips for managing acommissioning authority, and additional commissioning resource material.

The Commissioning ProcessThe commissioning process for control systems includes the following ac-t i v i t i e s :1. A commissioning provider/consultant is engaged by the owner.

2. The commissioning plan for the design phase is developed by the com-missioning consultant.

3. The controls are designed and project specifications are developed, in-cluding commissioning requirements for the construction phase. Thecommissioning provider conducts a focused review of the design.

4. A controls vendor is selected.

5. A commissioning plan for the construction phase is developed and final-ized.

6. The commissioning authority reviews and approves controls submittals.

7. The vendor installs and checks out the system and documents the pro-cess, with review by the commissioning authority.

Commissioning New EnergyManagement SystemsGuidelines and procedures

3-2

CHAPTER 3

FIGURE 3-1.The Commissioning Process

Controls vendor selected

CA develops design phase Cx plan

CA reviews design and specifications

CA develops commissioning plan

CA reviews controls submittals

CA reviews checkout documentation

CA develops functional tests

CA directs and witnesses functionaltests performed by vendor

CA approves facility staff training

CA reviews and approvesO&M manuals

Approval

Equipment passes?

Controls design andspecifications developed

Vendor installs andchecks out system

Controls vendorselected

Deficienciescorrected

CA = Commissioning Authority

Cx = Commissioning

YES

NO

RETEST

3-3

COMMISSIONING

8. The commissioning authority develops functional test procedures.

9. The vendor executes the functional test procedures with direction anddocumentation by the commissioning authority.

10. Deficiencies are corrected and retested.

11. The O&M documentation is reviewed and approved by the commis-sioning authority.

12. The commissioning authority approves the training plans and verifiesthat specified training is conducted.

13. Deferred seasonal testing is conducted later.

14. Near the end of the main warranty period (typically one year), thecommissioning authority returns to the site and reviews the currentsystem performance, interviewing the facility staff and helping to ad-dress any outstanding issues still under warranty.

Figure 3-1 provides a graphic summary of the above steps.

Procurement Methods and CommissioningChapter 2: Specifying and Selecting a New Energy Management System, de-scribed two primary methods for procurement of larger control systems—spec and bid, and design-build. The commissioning tasks remain essentiallythe same in either method. The main differences are 1) who the commis-sioning authority deals with and 2) when the design documentation is de-veloped. With the design-build method, the commissioning authority workswith the vendor’s team during design and construction. In the spec and bidmethod, the commissioning authority coordinates with the independentdesign engineers at the beginning of the project (and possibly throughoutconstruction if the designers have construction observation responsibili-ties). Generally, the commissioning authority does not work with the ven-dor until the construction phase.

Two features of the design-build approach make commissioning especiallynecessary: 1) the designers, vendors, and contractors are working contrac-tually together and may tend to minimize or even hide each other’s mis-takes; 2) documentation is generated later than in the spec and bid approach.Commissioning, which focuses on timely, complete documentation over-seen by an independent authority paid by the owner, helps offset thesepotential problems.

Elements of a SuccessfulCommissioning ProjectThere are five primary components of a successful commissioning project.

• Start early—before or at the beginning of the design phase.

• Have complete specifications, including commissioning specifications.

• Involve competent players.

• Develop a detailed commissioning plan.

• Follow the commissioning plan.

3-4

CHAPTER 3

Commissioning During DesignIt is considerably less expensive and disruptive to the construction sched-ule if design changes are identified early, during design, rather than later,during construction. For this reason, bringing a commissioning authorityon board during the design phase is valuable. In addition, the sooner thedesign and construction team members buy into the commissioning pro-cess, the smoother and more effective the project will be. This applies toboth design-build and spec and bid projects.

During the design phase, commissioning has the following objectives:

• Provide a commissioning-focused design and specification review.

• Ensure that the design and operational intent are clearly documented.

• Ensure that commissioning for the construction phase is adequately re-flected in the bid documents.

Design ReviewThe commissioning authority should cover at least the following topicsduring the review of the design documents:

Commissioning FacilitationVerify that the design documentation is clear and complete; that there aresufficient isolation valves, dampers, interlocks, pressure and temperatureplugs, pressure gages, thermometers, flow meters, and monitoring points;and that there are adequate trending capabilities to efficiently commissionthe system.

Control System and Control StrategiesReview HVAC, lighting, fire control, security control system strategies andsequences of operation for completeness, clarity, adequacy and efficiency.Review the capabilities and features of the specified system against theowner’s expressed wishes and needs.

Operations and MaintenanceReview the control system relative to efficient O&M and building control.For example, make certain that offsite alarm, monitoring and remote-accessfeatures are clearly understood and documented and that there is sufficientaccess around equipment for proper servicing.

O&M DocumentationVerify that the specified O&M documentation requirements are adequate.

TrainingVerify that the specified operator training requirements are adequate.

Commissioning SpecificationsVerify that bid documents adequately specify building commissioning, in-cluding the issues listed above . Vendors will rarely include commissioningin their bids, and it is difficult to get cooperation for commissioning whenit is added on later.

CommissionEarly

Commissioning identifies

needed improvements early in

the process, minimizing both

the cost of changes and delays

to the project schedule.

3-5

COMMISSIONING

Design and Operational IntentThe commissioning authority sees that the controls designer clearly andcompletely documents the intent behind the controls features specified andthat the operational and control sequences are fully documented as early inthe design phase as possible. Without this oversight, control sequencesmay be documented only in vague, general terms. If performance specifi-cations (specifying what the system will do, but not how the sequences willaccomplish it) are not followed up with full sequence documentation, thevendor’s site-based technician may develop important control sequencesand parameters without adequate input from the original controls or systemdesigner. Such onsite programming is generally poorly documented andrarely reviewed and may lead to inefficient or defective sequences. To al-low the commissioning authority to optimize sequences during design re-views, design intent and control sequences must be documented duringdesign. The Model Commissioning Plan and Guide Specifications referencedat the end of this chapter provides sample forms for developing designintent documentation.

Commissioning SpecificationsThe commissioning authority may help the specification writer to specifythe commissioning requirements for the control system using one of twomethods. The commissioning authority may provide a boilerplate commis-sioning specification, which the controls designer incorporates into the speci-fication and the commissioning authority then reviews for approval; or, thecommissioning authority may write the commissioning specification, whichthe controls designer then approves and uses in the specification.

Commissioning requirements should be explicit. The specifications shoulddescribe what systems and components are to be commissioned; what test-ing will be required; what testing documentation will be required; andwhat acceptance criteria will be used. This is especially critical for inter-faces with existing controllers or standalone controllers. Additional specifi-cation guidelines are found in Chapter 2: Specifying and Selecting a NewEnergy Management System.

Competent PlayersThere are three players essential to the success of a commissioning project:the commissioning authority, the controls vendor, and the project manager.Below is a discussion of the recommended requirements for each of theseindividuals.

Commissioning Authority

Selecting the right commissioning authority is the single most importantstep to a successful commissioning process. The commissioning authorityshould have excellent qualifications in commissioning project field experi-ence, control and HVAC systems troubleshooting, energy efficient strategiesand communication skills. The following list provides specific language

BuyerBeware

Controls vendors may claim to

have a commissioning program

in place, but remember:

•Vendor commissioning may

lack rigor and adequate

documentation.

•Just because the vendor has a

commissioning process “on the

books” does not mean the

vendor’s staff will execute it

adequately.

3-6

CHAPTER 3

that may be used in soliciting a commissioning authority. (The Model Com-missioning Plan and Guide Specifications referenced at the end of thischapter provides a full request for qualifications for a commissioning au-thority.)

Project Experience• Experience as the principal commissioning agent for at least three projects

over 100,000 square feet. (Increase or reduce the size of required projectexperience, depending on your project.)

• Excellent verbal and writing communication skills. Highly organized andable to work with both management and trade contractors.

Technical Experience• Extensive experience in the operation and troubleshooting of EMS, HVAC

systems and lighting controls systems. Extensive field experience. A mini-mum of five years in this type of work.

• Knowledge of building operation and maintenance and O&M training.

• Knowledge of test and balance of both air and water systems.

• Experience in energy-efficient equipment design and control strategyoptimization.

• Direct experience in monitoring and analyzing system operation usingEMS trending and standalone data-logging equipment.

• Experience in writing commissioning specifications.

Education and Credentials• A bachelors degree in mechanical engineering is strongly preferred and

professional engineer (P.E.) certification is desired; however, other tech-nical training and past commissioning and field experience are moreimportant than formal certifications.

Management Requirements• The member of the commissioning firm designated as the commission-

ing authority must be fully qualified and must be assigned to the projectfor its duration.

• The commissioning authority will ideally be an independent contractorand not an employee or subcontractor of the controls vendor.

Controls Vendor

Chapter 2 provides guidelines for obtaining the qualifications of controlscompanies and their key staff. Review these qualifications and call thereferences. Obtaining information about problems the vendor had in pastprojects may not cause you to change your mind about the vendor, but itwill alert you to areas to watch closely and/or discuss with the vendorbefore the problem is repeated on your project.

Project Manager

Your project manager should take an interest in following the commission-ing process and—most importantly—must openly support the commission-ing authority. The commissioning authority must have your full support,especially if the vendor’s staff resists full compliance with the commission-ing authority’s plan. The project manager should facilitate regular commis-

3-7

COMMISSIONING

sioning meetings and should process the commissioning authority’s requestsfor information and reports on possible deficiencies. With proper support,the commissioning process can be successful for all parties involved.

The Commissioning PlanA successful commissioning project needs a solid commissioning plan. Typi-cally, the commissioning authority writes the commissioning plan, whichshould assign responsibilities and deal with priorities and procedures. Agood commissioning plan incorporates the following elements:

• Objectives and scope

• Players and responsibilities

• Communication, reporting and management protocols

• Documentation requirements of the equipment installation

• Documentation requirements of the commissioning process

• Scope of manual testing and monitoring (specific)

• Recommended training format and verification

• Schedule

• Further details of required testing, documenting and reporting where thespecifications are weak (if applicable)

Putting the Plan into ActionThere are a number of tasks in a commissioning plan: installation and initialcheckout; operational checkout; functional testing; O&M documentation;and training. Below is a discussion of some of the most relevant issues foreach topic.

Installation and Initial Checkout

Before functional testing by the commissioning authority begins, requirethat an initial checkout (sometimes called a point-to-point and operationalcheck) be completed and documented by the controls vendor. This can bedone as part of the installation. (Refer to Appendix A for additional calibra-tion and setup procedure details.) Require that the documentation formsand procedures for the initial checkout be pre-approved by the commission-ing authority. These forms should contain a list of every control point in thesystem, along with a space to check as each point undergoes, and passes orfails, the following four tests:

1. Hardware Check• Verify wiring to each point and sensor location.

• Verify software point address in the control system.

• Verify that points are set up in the local device controllers.

• Verify that all points in the controller or sensor are communicatingproperly with the control system.

2. Software Load and CheckThis applies to controllers such as those found in terminal units; thecontroller is powered up and the approved software program (with

3-8

CHAPTER 3

setpoints, deadbands, etc.) is uploaded to the controller and proper com-munication again verified.

3. Calibrations• Verify that all sensors are located away from causes of erratic opera-

tion.

• For all sensors, check the sensor reading in the EMS against a recentlycalibrated test instrument. Calibrate as needed. (Enter an offset in theEMS, or use another suitable method.)

• For valve and damper actuators and states of other devices, verify atboth extremes of the actuator range that the reading in the EMS matchesa visual observation of the device. Refer to Appendix A: Sample Con-trol Specification Language, for complete procedure and requirementsfor calibration of sensors, points and actuators and to the Calibrationof Equipment section of Chapter 5: Strategies for Optimization.

4. Response CheckThis mainly applies to controllers such as those found in terminal units,but may be applicable to other equipment. Change setpoints such thateach controlled actuator (damper or valve) moves to the full open posi-tion. Verify that the CFM or flow, etc., at full open is per specificationand visually verify that the readout in the EMS is consistent with theactual conditions of the actuator. Observe proper staging. Repeat theprocedure to observe the actuator naturally going to the fully closedposition. Repeat for each actuator in the controller.

Operational Checkout

The controls vendor should be required to run each piece of equipmentthrough the entire sequence of operation to verify that the system functionsas intended. For small controllers like terminal units, the initial checkoutprocedures described above will suffice as the operational checkout, ex-cept for interaction tests with other equipment or tests for conditions suchas power failure and fire alarm.

The operational checkout by the vendor ensures that the system is readyfor functional testing and verification by the commissioning authority. Withoutthis assurance, functional testing often becomes a debugging process forthe controls contractor with a significant amount of the system requiringretesting and reprogramming. Vendors should do their own debugging be-fore the commissioning authority functionally tests the system.

Functional Testing

Functional testing verifies that the EMS and controlled equipment actuallywork as intended. The commissioning authority develops detailed test pro-cedures and documentation forms. Typically, each piece of equipment isrun through the entire sequence of operations, and all alarms are checked.The system is also tested by checking equipment interactions and inter-locks. This is done in start-up, shutdown, unoccupied, and occupied modes,as well as power failure, manual modes, full- and part-load conditions.

During testing, the controls vendor typically operates the equipment underthe direction of the commissioning authority. Tests may be manual, wherephysical conditions, setpoints, or point values are changed and the system’s

Testing IdenticalEquipment

For equipment types where there

are a large number of identical

pieces, only a small fraction of the

equipment needs to be tested.

Terminal Unit Example:

Randomly select 5% of terminal

units of each type for full testing

of all sequences.

If 10% of those fail, then another

5% should be tested.

If another 10% fail, then it will be

the contractor’s responsibility to

retest and document all

remaining units before

functional testing resumes.

3-9

COMMISSIONING

response is observed (at the control system terminal, visually, or by handheldinstruments) and documented. Other tests may require the vendor to trenda number of points in the system (if the points have been calibrated). Thecommissioning authority may then analyze the data in tabular or graphicalform, verifying proper sequencing and operation. Portable dataloggers arealso a useful and convenient way to monitor equipment and verify properoperation.

Areas that fail in the testing are investigated and corrected by the vendorand retested by the commissioning authority. Additional information onfunctional testing is found in the Functional Testing section of Chapter 5:Strategies for Optimization, and in the Manual Testing section of Chapter 6:Using EMS for Operational Diagnostics.

O&M Documentation

Facility staff need complete, clear, and accessible documentation about thecontrols system to use it efficiently. The commissioning authority shouldmake sure that documentation follows the requirements in the specifica-tions. Of special importance is as-built documentation, which is often pro-vided before functional testing is complete. Since functional testing alwaysresults in some changes, corrections, or enhancements to the control se-quences, the commissioning authority must verify that the final as-builtsreflect these changes. (Refer to the O&M Documentation section of Appen-dix A: Sample Control Specification Language, for additional details.)

Training

The specifications should require the vendor to provide a training agendafor review by the owner and commissioning authority. The plan shouldindicate who will do the training; the qualifications of the instructor; thetopics covered, with the time expected on each topic; the technical rigor ofeach subject; and any videotaping desired. The commissioning authorityensures that the training actually takes place as planned. (Refer to the Trainingsection of Appendix A for additional details.)

Tips for Managing the Commissioning Authorityand ProcessThe following are a list of essential tips that will assist the facility manager,project manager or owner’s representative in managing the commissioningauthority and the process.

Support and Scope

• Hire a well-qualified commissioning authority.

• Have a comprehensive and clear scope of work for the commissioningauthority.

• Read the commissioning specifications and the commissioning plan frontto back.

• Let all players know you support your commissioning authority.

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CHAPTER 3

Reporting

• Have clear reporting and paper paths and request-for-information pro-tocols.

• Insist on frequent progress reports and updates from the commissioningauthority.

Schedules and Meetings

• Follow through in a timely manner on your tasks (scheduling meetings,testing, issue and document reviews, conflict resolution, etc.).

• Make sure that commissioning gets included in the master schedule.

• Schedule or facilitate regular commissioning meetings.

Deficiencies

• Have the commissioning authority keep a continuous current deficiencyor issues log, with a record of the resolution.

• Develop a clear policy on dealing with identified deficiencies.

• See that all deficiencies are corrected in a timely manner.

• Near the end of the project, have the commissioning authority and theproject manager go through the control specifications line-by-line toensure all requirements are being met.

Further Resources

American Society of Heating, Refrigeration, and Air-conditioning Engineers(800/527-4723), “Building Commissioning,” ASHRAE Applications, 1995

American Society of Heating, Refrigeration, and Air-conditioning Engineers(800/527-4723), ASHRAE Guideline 1-1996, The HVAC Commissioning Pro-cess, 1996

Heinz and Casault, The Building Commissioning Handbook, APPA: TheAssociation of Higher Education Facilities Officers (703/684-1446), 1996

Portland Energy Conservation Inc. (PECI) and U.S. Department of Energy,Model Commissioning Plan and Guide Specifications, 1997(download at http://www.teleport.com/~peci)

C H A P T E R

Often service contract options are the last thing considered whenpurchasing an EMS, yet without proper maintenance and operation,

these expensive and sophisticated systems frequently end up underused,overridden, and blamed for any number of O&M problems. For an EMS toremain cost-effective, long-term maintenance should be considered earlyin the project-planning phase.

The purpose of this section is to help the building owner and managerunderstand what types of contracts are available, who provides them, andhow to how to make the best choice among them.

EMS Service Contract ProvidersThe major providers of EMS service contracts are:

1. EMS ManufacturersA manufacturer may be the sole distributor and installer of the system itproduces, or it may qualify other firms to distribute and install its systems.Most manufacturers of EMS offer a variety of service agreements or con-tracts for their systems.

2. Mechanical ContractorsMechanical contractors install, repair, and perform O&M on all types ofmechanical equipment, including EMS. They may also distribute a particu-lar manufacturer’s EMS and provide maintenance agreements or servicecontracts for that system. Their service technicians are factory-trained bythe manufacturer of the EMS they distribute.

3. National Maintenance Service FirmsNational maintenance service firms mainly serve large retail chains andowners of multiple buildings. These firms qualify mechanical contractingbusinesses throughout the country as their subcontractors; the subcontrac-tors are then considered part of their service team. This type of nationalfirm may also be a full-service mechanical contractor with its own techni-cians and distribution rights to a particular manufacturer’s EMS. Their ser-vice technicians are trained by the manufacturer of the EMS.

Service Contracts forEnergy Management SystemsOptions and recommendations

BuyerBeware

All three types of service providers

discussed at left distribute and

install the system they service. But

some maintenance firms will

service any EMS, even if they

don’t distribute the system. Unless

the EMS is simple and the need for

changes to either the system or the

building is rare, it is risky to have

someone other than the supplier

of the system service it. A

contractor may claim to have

trained technicians, but most

manufacturers rigorously train

only those technicians whose

companies have the distribution

rights to their system.

Manufacturers are not interested

in training their competition.

4-2

CHAPTER 4

Various Types of Service Contracts

In the EMS industry, there is no standard or set of definitions for the variouskinds of service contracts or agreements. Each manufacturer or distributorputs together a unique package of service offerings. The package oftenconsists of three or four types of contracts at different levels of comprehen-siveness and with different features. Below, we briefly discuss five tradi-tional types of contracts:

• Full-maintenance agreements

• Software monitoring agreements

• Full-service agreements (combination of the above two)

• Preventive maintenance agreements

• Open or flexible agreements

Within these five types, there can be many variations, depending on anowner’s needs and the contractor’s willingness to modify or customize ser-vice agreements. Many EMS vendors also provide service contracts that notonly include the EMS but also all other building equipment and systems.For the purpose of this document we will only discuss service contracts forEMS.

1. Full-Maintenance Agreement

The full-maintenance agreement may be thought of as an extended war-ranty. This type of contract is generally purchased following the installationof a new system. For a set annual fee, the contract covers all labor andmaterials for EMS hardware failures and generally includes an emergencyresponse arrangement. Both the duration of the agreement and the emer-gency response feature are usually negotiable. Typically, these contractsare purchased to cover a one- to five-year period. One of the main advan-tages of this type of contract is ease of budgeting. The owner knows ex-actly what maintenance will cost no matter how sparse or extensive therepairs are for the contract period. However, this type of contract is usuallyexpensive because of the risk to the provider. Contracts are often moreexpensive for older systems because they are more likely to fail. The con-tract price should be closely scrutinized. The cost should reflect the ageand condition of the system. The owner should compare the total cost ofthe service contract to the cost of a new system. Over the contract period,the cost of the contract may be close to or the same as the cost for a newsystem. When evaluating a contract of this type, consider the fact that thenewer distributed (DDC) systems are much less prone to failures than theolder mainframe type systems. Failures of any size in a distributed systemtypically do not become catastrophic as long as the system is well groundedand surge-protected. In addition, if there are well-trained onsite staff to domost of the repairs for the system, this type of contract may be inappropri-ate.

4-3

SERVICE CONTRACTS

2. Software (Remote) Monitoring Agreement

The software-monitoring type of contract may be purchased anytime dur-ing the life of the system. With this type of contract, the service providerremotely monitors the EMS for problems. When a problem occurs, thedecision on how to remedy it depends on the contract arrangements. Thecontractor may have the authority to make certain limited decisions abouthow to solve particular problems. For example, the contractor may havethe authority to raise or lower setpoints within a certain range to alleviatecomfort problems. However, some owners may require contractor notifica-tion whenever any problem arises. Usually, major or permanent changes tothe system regarding scheduling, setpoints, or programming are done atthe request of the owner. Emergency response arrangements vary accord-ing to the level of involvement of the service provider in actually repairingthe system.

The software monitoring contract is most appropriate for facilities whereknowledgeable staff is not always available and/or where the need forconsistent and reliable operation is critical.

3. Full-Service Agreement

The full-service agreement combines the two contracts discussed aboveand addresses both hardware and software issues. The full-service agree-ment is often purchased by owners who have complex multiple facilitiesand prefer to outsource most work that is not a core business component.This is the most expensive service contract. An emergency response ar-rangement is typically part of the agreement.

4. Preventive Maintenance (PM) Agreement

The PM agreement is generally purchased for a fixed fee and includes apreset number of scheduled visits each year. The purpose of this type ofcontract is to periodically inspect the system for problems and perform theagreed-upon PM activities that keep the system in good working order andthe programming current for the season. The contract may or may notinclude any arrangements regarding emergency calls. The main advantageof this type of contract is that it is generally less expensive than either thefull-service or full-maintenance contracts. It also provides a focus on high-quality preventive maintenance. However, budgeting and cost control foremergencies, repairs, and replacements are more difficult, because theseactivities are generally done on a time-and-materials basis. The owner car-ries most of the risk.

5. Open or Flexible Agreement

Another option is the purchase of a block or pool of hours for labor at a setannual fee. Under this arrangement, the owner may use these hours for arange of needs from programming to installing hardware or upgrades. If, atthe end of the year, the hours are not exhausted, some service providersallow the owner to roll them over to the next year. This type of arrange-ment may be purchased alone or in combination with several of the otheragreements discussed above.

SystemBackup

Some remote monitoring

agreements require the provider

to back up the system daily. This

usually includes downloading

every panel and all config-

urations each day at a set time,

such as midnight. This feature

may be available in any type of

contract and is valuable for

owners of complicated, failure-

sensitive systems.

4-4

CHAPTER 4

6. Mix, Match, and More.

The following discussion highlights some cost-effective ways of obtainingappropriate, high-quality service agreements.

Owners with well-trained and available onsite staff should consider pur-chasing any combination of the following service arrangements:

• Flexible agreement

• Preventive maintenance agreement

• Long-term purchasing agreement

The long-term purchasing agreement allows the owner to keep an in-ventory of EMS parts onsite for an agreed-upon time, usually three to fiveyears. The amount of inventory is based on the likelihood of EMS failuresand the urgency of the possible repair. Parts that seldom fail or are notcritical to the owner or tenant’s business are generally left out of the inven-tory. For example, the failure of a control panel board for a packagedrooftop unit serving a major tenant would be considered urgent; the failureof a space temperature sensor for an infrequently used conference roomwould not.

Although an owner may keep an inventory of parts worth several thou-sands of dollars, under this agreement a part is not paid for until it is used.The failed part is removed and sent back to the manufacturer. The agree-ment is usually negotiated so that the owner pays published list price forthe parts less a certain percent (20% to 60%). At the end of the agreementperiod, the contract may be renewed or the unused inventory may bereturned to the supplier at no further charge. The fees paid to the supplierfor this type of agreement are minimal and are generally related to theinterest rates and property taxes on the inventory. The long-term purchas-ing agreement may be effectively coupled with a preventive maintenance(PM) agreement from the same supplier that offers annual software, firm-ware, and hardware upgrades plus any agreed upon PM activities and emer-gency response arrangements.

Another cost-effective arrangement is the purchase of a pool of labor hoursfrom the vendor based on an assessment of programming needs for theyear. This arrangement works well for owners of somewhat smaller build-ings that have building operators with expertise in EMS operation. Combin-ing this with a PM contract that includes system upgrades often providesthe owner with the most quality at the least cost.

Some EMS suppliers offer a technical support agreement. With this op-tion the owner can purchase a range of technical support activities fromone day of hands-on training for their building operators to a weekly onsitevisit by a technician (coach). When the agreement requires a technicalcoach for the building operators, the duration of the arrangement may lastanywhere from a few weeks to years. This agreement can also be coupledwith several of the other types of contracts, depending on the owner’sneeds.

4-5

SERVICE CONTRACTS

What To Consider When Selecting a ServiceAgreement

Selecting an optimal, cost-effective service agreement for the EMS can beconfusing. The following list of considerations are meant to help the ownerand manager develop objectives for their contract and evaluate the fit ofvarious contracts to their needs:

• Owner’s overall economic objective

• Importance of system performance to the bottom line

• Training and availability of in-house staff

• Size and complexity of the EMS

• Sophistication of the required control strategies

• Budget constraints

• Objectives for purchasing a service agreement

Owner’s Overall Economic Objectives

The first thing to consider is the owner’s economic commitment to aproperty. If the owner is a short-time investor and intends to sell withintwo years, a basic PM agreement with repairs and emergency servicebilled on a time-and-materials basis may be the most appropriate arrange-ment. If the owner has a long-term investment in the property, morecareful evaluation of all the factors is worthwhile.

Importance of System Performance to the Bottom Line

EMS performance may contribute to economic success. Take, for example,a building housing a single tenant, where the owner is responsible for allthe building operation and maintenance. Not only is the productivity ofthe tenant’s employees critical to the tenant’s business, but the owner’sability to keep the tenant may depend on how well the control systemmaintains comfort. Retail profits may also be affected by how well theEMS operates. For example, if the EMS humidity controls are not wellmonitored and maintained, products sensitive to excessive moisture canbe lost. In sensitive laboratory environments, the control system is criticalto bottom-line success: Experiments can be jeopardized when tempera-ture, humidity, and pressure are not consistent.

Training and Availability of In-House Staff

For a facility without expert in-house building staff, a rigorous type ofservice contract is recommended. Even if there are expert building opera-tors on staff, EMS upkeep may be too time-consuming for them, and aservice contract may still be necessary. The more control expertise andavailable time the building staff has, the less critical the need for a rigor-ous service contract. In some cases, purchasing a block of programminghours along with a minimal PM contract that includes system upgradesmay be sufficient.

4-6

CHAPTER 4

Size, Complexity, and Sophistication of the EMS

The size of an EMS alone does not usually dictate the need for a servicecontract. The complexity of the system and the sophistication of the con-trol strategies have a greater impact on service requirements. A largefacility with several buildings and a significant number of rooftop pack-aged units (RTUs) with integral controls may need the EMS only to en-able and disable the RTUs according to a simple time-of-day schedule.An expensive monitoring or full-service contract is not appropriate forthis situation. In contrast, a relatively small facility with a full DDC systemcontrolling the heating and cooling plant, along with a VAV air distribu-tion system and space static pressure, would require a rigorous level ofservice.

Budget Constraints

Few owners or managers have an unlimited budget for operating andmaintaining an EMS. Budget constraints are often the deciding factor inchoosing a service agreement. However, installing an expensive and com-plicated system without the budget to maintain it generally means thatany savings initially gained from the system will quickly disappear. Own-ers and managers need to avoid being “penny wise and pound foolish”when it comes to selecting service agreements. An appropriate servicearrangement will often pay for itself.

How MuchDoes It Cost?

The price of service contracts

varies dramatically depending on

the type of contract, the size and

complexity of the system, and the

importance of the system to the

owner’s operations. Service

contracts can range from a few

hundred dollars per year to tens

of thousands of dollars per year.

Owners and managers must

analyze and prioritize their needs

in order to get the most cost-

effective options.

C H A P T E R

Strategies forOptimizationUsing EMS to improve building control and efficiency

Once an EMS is in place and fully operational, the facility managerwho will supervise its operation may look toward optimization. In

this chapter, we use the term “optimization” to refer to activities that movebeyond common EMS routines and into customization for maximum oc-cupant comfort and minimum energy consumption. Because buildingsare dynamic, with frequent changes in floor plans, space use, weatherconditions, plug loads and occupant densities, EMS optimization is anongoing process.

Historically, energy management systems have been installed to controlequipment with greater accuracy and automation than is possible withmanual or pneumatic controls. Today, forward-looking building ownersmay install state-of-the-art EMS with several agendas in mind:

• To increase occupant comfort and improve building operation.

• To “take control” of the building (assuming the old system was notadequate).

• To allow interoperability with other facilities, perhaps by taking advan-tage of a campus-wide LAN.

• To reduce energy use and improve the bottom line.

This chapter examines steps that can be taken to optimize EMS operation,with particular attention to strategies to reduce energy consumption andimprove occupant comfort. This chapter will also help owners and man-agers to understand and master the full capabilities of their EMS. Even ifsome of the control strategies discussed are not applicable at present,they may provide ideas for future upgrades.

5-2

CHAPTER 5

Basic EMS Capabilities

Before trying to optimize a system, it is important to understand basic EMScapabilities. Features may vary widely from model to model, but somebasic capabilities are almost universal. This section will discuss several ofthe standard EMS capabilities:

• Scheduling• Setpoints• Alarms• Safeties• Basic monitoring and trending

With each of these features, there are opportunities to move beyond mini-mal utilization without significant effort or complexity.

SchedulingEnergy management systems are sometimes referred to as “glorified timeclocks” because many of their capabilities are frequently disabled or elimi-nated. In the past, these glorified time clocks have not even done a goodjob of scheduling. Today’s systems, however, allow for greater flexibility inscheduling, defining not only ON/OFF times, but setpoints as well. Withmultiple scheduling scenarios available in most EMS, even elementary timeclock and scheduling features can offer significant savings. Clearly, the firststep in smart scheduling is to shut down unnecessary equipment when it isnot needed. Given the complexity of a building and the amount of equip-ment with potentially different schedules, this task requires some effort,but taking control of schedules may still be the quickest and simplest wayto see an immediate reduction in energy bills.

It is recommended that you check on schedules periodically to assess whetherthey still apply. Make sure zone HVAC schedules are consistent with light-ing and occupancy schedules. Lighting sweep schedules, which turn offlights at scheduled times, should be set so that they work for tenants andcleaning staff to minimize both lighting on-time and nuisance overrides. Inaddition, the following EMS capabilities should be investigated and used toreduce unnecessary equipment use.

Daily Scheduling. Many EMS software packages provide for up to 5 or 7user-configurable start-and-stop schedules for each piece of machinery foreach day of the week. Customize these schedules to fit your needs andreduce the time equipment is running unnecessarily.

Calendar Scheduling. In addition to typical holiday schedules, calendarscheduling allows for greater flexibility in EMS operation. Schedules can beprogrammed to service unusual events such as production schedules orseasonal changes in occupancy or occupancy hours. The EMS operator canenter schedules for any number of control points for any date during theyear. Depending on the EMS software, calendar schedules may be erasedonce the dates have passed and schedules were successfully implemented.

EnhancementPossibilities

•Your alarm system may be setup properly, but are youconsidering all routing andautomated messaging options tominimize problem-solvingresponse time?

•Are you recalculating yourwater and air temperaturesetpoints to improve efficiencyand reduce reheat orsimultaneous heating andcooling as loads change?

•Are you scheduling each pieceof equipment to minimizeunnecessary on-time?

5-3

OPTIMIZATION

Alternatively, the scheduled dates may repeat in subsequent years (as is thecase with holiday schedules). Calendar schedules allow the building man-ager to automatically provide space conditioning only when and where it isneeded. Automatic conversion to and from daylight savings time is anotherconvenient feature in many systems.

Exception Scheduling. If there is an exception to the regular schedule(e.g., a half day or longer hours than normal), this feature allows you toprogram the exception for that day only rather than changing the regularschedule. Once the exception period is passed, the program returns to theoriginal schedule.

SetpointsSetpoints range from those inside equipment logic, which are rarely changed,to space temperature setpoints, which seem to need constant adjustment.Some setpoints are defined by the operator and associated with a schedule;others may be adjusted by internal calculations of the program (e.g., resettemperatures or pressures).

Space Temperature Setpoints. The building manager’s job, among otherthings, is to maintain occupant comfort while identifying ways to reduceenergy consumption. Controlling the space temperature may be the singlemost time time-consuming and problematic task a building operator dealswith. Often, the possibilities for reducing energy use by altering spacetemperature setpoints are not investigated for fear of adversely affectingcomfort. This may be the case at times, but large multi-zone buildings withDDC can present opportunities to move beyond a traditional building-widesetpoint. The following information should be reviewed when consideringspace temperature setpoint changes:

• Time of day

• Number and fluctuation of occupants in zone

• Humidity conditions

• Size of zone

• Location of zone

• Zone exposure (perimeter or core, south or north, etc.)

• Impact on reheat or simultaneous heating and cooling

• Impact on pumping, fan, or plant efficiency

• Equipment in zone (e.g., computers or laboratory equipment).

Consideration of all these factors could lead, for example, to a well-justifieddecision to allow the afternoon summer temperature in a north-facing zoneto drift up by 2 degrees. Additionally, an entire floor of tenants with seden-tary jobs could have a warmer setpoint than a floor of more active workers.Remember that comfort is a function not only of space temperature butalso of radiant temperature (direct sunlight), airflow, and humidity.

It is important to carefully analyze the net impact on adjusting space setpoints.

5-4

CHAPTER 5

For example, increasing the zone setpoint during the swing season to savecooling energy may result in increasing reheat energy in zones that requirereheat.

Dual Setpoint Control (Deadband). The most common strategy for opti-mizing space temperature setpoints is to have separate heating and coolingsetpoints or one setpoint with a wide deadband (greater than 4ºF). Thislowers the potential for simultaneous or overlapping heating and cooling,thereby reducing wasted energy and comfort complaints.

Other Setpoints. The building operator should be familiar with a numberof other basic setpoints. It is critical to have an understanding of the pur-pose behind each setpoint and the impact on energy and other systemswhen the setpoints are altered. An up-to-date consolidated list of all pri-mary setpoints as part of the system documentation is very useful.

AlarmsRegistering and recording alarms is a critical part of any EMS. In addition tobasic alarm functionality, an EMS provides options in specifying how alarmsare monitored, reported, routed, and ultimately dealt with. For any moni-tored or controlled point, most systems’ basic alarm functions can be set upto register and display the following:

• Equipment failures

• Sensor failures

• High parameter value (temperature, pressure, etc.)

• Low parameter value (temperature, pressure, etc.)

• Invalid temperatures (sensor is being tampered with)

• Manual override of machinery at remote locations

• Communications problems

Alarm Features. Alarms are fundamental and critically important, so mostsystems will need little or no extra configuration to provide basic alarmfunctionality. However, building managers benefit from alarm-handling fea-tures that assist in formulating a quick and accurate response. Alarm mes-saging provides extra information on the source of the alarm, such as thestate of the equipment when the alarm was generated. Additional messagescan sometimes be attached to alarms as well. Alarm routing is a feature thatgives flexibility in delivering messages to a prescribed series of outputs(e.g. computer screens, printers, or remote monitoring sites via modem). Inaddition, some systems have a paging feature that works with alphanu-meric pagers where the actual alarm text with current point value is dis-played on the pager. Responses for some noncritical alarms can be dealtwith via automatically pre-programmed alarm handling routines.

Often there is a distinction between an “alarm” and a “warning.” A pointmay generate a warning if it is slightly out of range but an alarm if it issignificantly out of range. Once the operator understands the alarm pro-gramming of the EMS, there is often latitude to use some creativity in defin-ing points and alarms. For example, the difference between a temperature

BasicSetpoints

• Supply air temperature

• Mixed air temperature

• Coil discharge air temperature(hot and cold deck)

• Heating water

• Boiler lockout

• Chiller lockout

• Chilled water supplytemperature

• Entering condenser watertemperature

• Duct static pressure

• Economizer changeover

• Space temperature (summerand winter)

• Space temperature deadband

• User thermostat adjustmentrange

• Pump or piping differentialpressure

• Return air relative humidity

• Supply air relative humidityhigh limit

5-5

OPTIMIZATION

and its setpoint may be a more relevant point to alarm than the tempera-ture itself. Alarms are a potentially powerful tool to be used in managing abuilding, but if not well defined they can become an annoyance or evenworse.

Nuisance Alarms. If alarms are poorly defined and too easily set off, theoperator may acknowledge alarms without review just to get rid of them.This could cause real problems if a significant alarm comes in. A log shouldbe created of all alarms to be reviewed periodically to improve the alarmrules and limits. For those facility managers who have little time to doanything but respond to alarm after alarm, this approach is worthwhile.Furthermore, if enhanced alarm handling features are available butunderused, it may be that full utilization will result in faster problem-solv-ing response time and better documentation for future reference.

SafetiesSafeties are sequences programmed into an EMS that are automatically ini-tiated to protect equipment, property, or life. The condition that initiatesthe safety sequence may also generate an alarm (high duct static fan shutdown, freeze condition fan shut down, etc.). Using safeties can protectequipment and the building itself from damage and may also reduce oreliminate the need for alarm reporting to remote sites to engage an afterhours emergency service call. For example, a high-water condition in thecooling tower may indicate a clogged intake screen or faulty make-up valve.This condition is serious enough to require immediate attention for a towerwithout a separate float control. After hours, an alarm would be required tosound offsite for immediate service. A safety sequence would simply closethe make-up water valve and/or shut down the chillers until the normalfacility operators could deal with the issue the following morning.

Safeties that protect life and equipment (freeze-stats, high pressure limits,and smoke detectors) should not rely on software and programming func-tions to work—they should be hardwired.

Basic Monitoring and TrendingIn addition to controlling equipment, EMS has the basic capability to moni-tor or record various parameters of equipment operation. In EMS terminol-ogy, monitoring is referred to as trending. Trending can be executed onmost points that control equipment, for other monitored-only points thatmay have been installed, and for some software or virtual points (calcu-lated values such as resets).

Monitoring and trending through EMS offer significant advantages over otherdata measurement methods. With the sensors already in place to monitorequipment, the cost of monitoring through EMS is often less than that ofpurchasing or renting other devices or taking spot measurements withhandheld instruments. The communications structure of EMS facilitates moni-toring many data points simultaneously. Since trend data are an actual

What Isa Trend?

For analysis and diagnosis of

building equipment performance,

a single parameter point of data

is insufficient—a picture of what

the parameter is doing over time

is needed. A trend is a collection

of data in chronological order.

5-6

CHAPTER 5

record of performance, EMS trends are often used to verify equipment op-eration, energy conservation project results, and energy savings performancecontracts.

Trending Points. Ideally, the EMS should be capable of providing the fol-lowing types of information:

• Temperature• Pressure• Damper and valve position commands, including variable frequency

drive control signals• Virtual points (internal calculations such as enthalpy or changing

setpoints and targets)• (ON/OFF) status or stage• Flow rate (water or air)• Alarm state• Current• Power demand (kW)• Energy consumption

(kWh, therms, gallons, etc.)• Revolutions per minute (RPM)• Virtual points

Some types of data points are not commonly used because of the cost oftheir sensors or transducers. These include air and water flow rates, powerdemand and energy consumption. If a necessary point is not available, it isusually a simple matter to add it, especially when there are open inputchannels in the panel.

Basic Trending. There are two basic trend types—a data stream and achange of value (COV). In a data stream, the EMS at each time intervalgathers the current value of a data point and stores it with the exact time theparameter was polled. A COV trend records the time and parameter valueonly when the parameter changes by a preset amount.

Instructions can be given to the EMS to track more than one data point at thesame time. The data is stored in the control field cabinets or the centralcomputer. When the cabinet memory is full, it may download the trend datato the central computer’s hard drive or begin erasing the oldest data. It isimportant to understand how to set up this memory and data managementin your system.

The data can be retrieved and viewed in a tabulated numerical form on thecomputer screen or on a hard-copy printout or, preferably, by a graph of thedata. Many energy management systems have features that allow trend datato be viewed graphically. Some even provide a real-time view of the graphas events are actually happening, although these tools are typically inflex-ible. For more rigorous graphical analysis, the data may be exported to acommercial spreadsheet program. EMS software will typically have somedefault trend plots (sometimes called history logs) already set up in thesystem. Other custom trends can be set up and initiated at will.

5-7

OPTIMIZATION

Trends can be useful for dealing with comfort problems (trend the terminalair flow and coil valve position), documenting conditions (trend the spacetemperature over time) or troubleshooting equipment malfunction (trendchange of value for the static pressure sensor to detect hunting). Figure5-1 provides an actual example. It shows that as the outside air temperaturegoes down, the chilled water flow also goes down, as expected, since thecooling load is tied to outside air temperature. However, the speed of thechilled water pump (current is used as a surrogate for speed) remains con-stant even though it is controlled with a variable speed drive, indicating amalfunction somewhere in the system.

For more detailed information on trending, see Chapter 6: Using EMS forOperational Diagnostics. For information on using spreadsheets to analyzedata, see Appendix B: Using Spreadsheets for Graphing and Analyzing TrendData.

Prerequisites for OptimizingEMS OperationsFor EMS optimization, it is critical to know the current status of your sys-tem—what it was intended to do and how well it is doing it. Whether youare installing a new system, adding new features to an existing system, orworking to improve your current system, take time to examine the follow-ing items before attempting significant enhancements:

• EMS Documentation. Make sure it is adequate.

• Sequences of Operation. Gather, examine and understand them.

FIGURE 5-1.Example of Trend Graph

Date Time

CHW

GPM OSAT

CHWPump

Amps

17-Oct 5:00 PM 549.69 71.19 52

17-Oct 5:15 PM 578.56 70.56 52

17-Oct 5:30 PM 562.19 70.38 52

17-Oct 5:45 PM 529.75 69.94 52

17-Oct 6:00 PM 445.38 69.25 52

17-Oct 6:15 PM 517.25 68.5 52

17-Oct 6:30 PM 393.44 68.5 52

17-Oct 6:45 PM 388.31 68.19 52

17-Oct 7:00 PM 448.13 67.69 52

17-Oct 7:15 PM 486 67.69 52

17-Oct 7:30 PM 407.06 67.38 52

17-Oct 7:45 PM 411.75 66.75 52

17-Oct 8:00 PM 432.88 66.25 52

17-Oct 8:15 PM 402.38 65.63 52

17-Oct 8:30 PM 401.25 65.19 52

17-Oct 8:45 PM 426.25 64.69 52

17-Oct 9:00 PM 426.63 63.56 52

0

10

20

30

40

50

60

70

80

16:48 21:36 2:24 7:12 12:00 16:48 21:36

0

100

200

300

400

500

600

700

800

Time (10/17 - 10/18)O

utsi

de A

ir Te

mpe

ratu

re (F

)

Chilled W

ater Gallons per M

inute

Trend Data Trend Graph - Chilled Water System

CHWGPM

CHWP Amps(Constant at 52Amps)

OSAT

5-8

CHAPTER 5

• Current Control Strategies. Examine and understand them.

• Calibration of Equipment. Calibrate all sensors and actuators.

• Functional Testing. Make sure equipment is operating as intended.

These topics will be discussed in the following sections.

EMS DocumentationWhen embarking on optimizing your EMS, it is necessary to assess the stateof your documentation and bring it to a satisfactory level in order to ad-equately understand and troubleshoot your system. Documentation con-sists of user manuals, product literature, software help files, control drawings,written sequences of operation, points lists, program code, and other mate-rials that describe the particulars to your installation. These support itemsare essential to assuring the long-term integrity of the system.

Unfortunately, even for new installations, system documentation is not al-ways provided in an easily usable form. Sometimes documentation is sim-ply missing; other times the operator is hindered by too much poorlyorganized documentation.

There are two basic types of EMS documentation: system and application.

System Documentation consists of those materials (usually reference manu-als) included by the manufacturer to explain and document a particularsystem. System documentation may contain large amounts of information,but that information may not be easy to find and use.

Organizing the product documentation logically, adding labeled dividertabs, culling irrelevant product data, etc., can make the system informationconsiderably more accessible.

You may also need to augment your system documentation. After receivingall available manuals from the vendor, check to see if you need to compileadditional materials yourself. Often, you will want to add supplementaryinstructions and documentation on features that are often used. More in-depth technical information is usually available from the controls vendor.Make sure you have received any documentation from past alterations orupgrades.

Application Documentation. Information specific to your EMS installa-tion can be found in the application documentation. This includes materi-als such as up-to-date control drawings and schematics; checkoutdocumentation; written sequences of operation; a points list; and ongoinglogs of system and controlled equipment changes. Because programmingand EMS points are likely to evolve over time, it is important to have aprocess for keeping application documentation up to date. The informa-tion can be difficult to assemble, but it is required in order to get the mostfrom your system.

Points lists and time-of-day schedules can easily be printed out. If yourvendor cannot supply missing information, you may need to develop yourown schematics or control drawings.

Essential Skillsfor Optimization

To fulfill the prerequisites for

optimization, a building operator

must be well-trained in all aspects

of the EMS operation,

particularly:

•Analyzing, determining andchanging setpoints

•Obtaining readouts, trend logsand other reports from thesystem

5-9

OPTIMIZATION

Obtaining Sequences. Obtaining clear, correct, and complete control se-quences with setpoints, lockouts, and parameter schedules for each piece ofequipment is normally the biggest documentation challenge. Copying (orprinting) critical information from equipment setup screens is a start. Theactual program code, particularly the programmer’s comment statements,can also yield sequence information. Make sure you have access to an elec-tronic or hard copy of the code. You don’t have to know how to program tofollow the logic of most control program code once you have been given afew syntax pointers. Obtain help from your vendor if necessary. An addi-tional benefit of constructing application documentation is that a compari-son of the sequence of operations with the actual programming may uncovererrors in the programming.

Original specified sequences or control vendor sequences should be gath-ered and carefully reviewed and annotated to reflect what is really happen-ing in your building. As a last resort, you may need to experimentally observeequipment operation under varied conditions (simulated or real) to developsome sequences.

Sequences of OperationSequences of operation are the actual commands and actions that an EMScarries out: performing calculations, opening valves, moving actuators, etc.Accurate and complete control sequences are absolutely critical for systemoptimization. Often, the optimizing improvement consists of fine-tuning orchanging the current sequence to a better one. Also, if complete sequencesare not known, particularly regarding interlocks to other equipment, changesthat improve one area may have negative impacts in other areas. For ex-ample, one might think that resetting the duct static pressure setpoint as lowas possible, subject to zone demand without any limitations, is a good strat-egy. However, an understanding that the terminal box may have erraticcontrol below 20% design flow would suggest a lower bound on the staticpressure reset to avoid adverse effects.

Ideally, sequences are clearly documented during design and updated at theend of installation. However, sequences, especially basic ones, are some-times omitted from drawings or binders. Moreover, changes to sequencesare sometimes made “on the fly” during installation or during callbacks, withno written record to show design intent or sequence changes.

Even when sequences are included in the documentation, they are frequentlyincomplete, unclear, or partially incorrect. Often, sequences documentationfrom the original specs varies considerably from sequences documentationfrom the controls vendor with no indication as to which version is correct.(Obtaining or developing sequence documentation was covered in the Ap-plication Documentation section above.)

This chapter covers both the control strategies themselves (demand limiting,optimum start/stop, etc.) and some of the primary sequences of operationand key parameters required to implement the strategies. Often the controlsystem software will come equipped with strategy menus or have potential

Minimum SystemDocumentation

•Product literature on systemcomponents, including valves,sensors, actuators, etc.

•Operator/user guide (how toaccess and use the terminal)

•Technical engineering manual(operations and detailedprogramming and use guide)

MinimumApplicationDocumentation

• Points list

• Current time-of-day schedulesfor each piece of equipment

• Up-to-date and completecontrol sequences for eachpiece of equipment

• Up-to-date and completecontrol drawings for eachpiece of equipment

5-10

CHAPTER 5

software upgrades for common strategies. Generation of sequences fromscratch occurs mainly for specialized or advanced control strategies.

More than any other information, the actual sequences of operation give themost insight into the operation of your building systems. Without them, it isdifficult to determine whether particular strategies are effectively designedor properly carried out.

Current Control StrategiesControl strategies are made up of a combination of control sequences. Onceyou understand your current sequences, you can plan future strategies. Askyourself these questions:

• What strategies have been attempted in the past? If strategies were at-tempted and subsequently abandoned, why?

• What strategies are currently up and running?

• What strategies run smoothly as designed?

• What strategies require significant maintenance and ongoing fine-tuning?

• What is the intent behind current strategies?

• Are current strategies periodically assessed for effectiveness?

• Are current strategies delivering quantifiable energy savings, improvedcomfort, or improved control?

Refer to Table 5-1 for a list of control strategies.

Company Goals and Objectives. A clear understanding of the owner’s ortenants’ energy management goals and budgeting policies is important be-fore beginning a system tune-up or optimization. If a primary goal in EMSoperation has been comfort management or process control, with little con-cern for energy use, you face an entirely different challenge than if the maingoal has been maximizing energy efficiency. If you have not been involvedwith EMS objectives in the past, interview those who have been to find outhow best to approach an EMS optimization project.

Calibration of EquipmentCalibration is the process of adjusting sensors and actuators so they readand move correctly relative to their limits and the initiating stimulus. Ther-mostats, transducers, valve and damper actuators, and other devices all re-quire calibration. Pneumatic actuators are particularly prone to drift. Moreover,it is very common for DDC controls to be installed without sufficient calibra-tion. These devices should be calibrated before optimization of your systemis begun.

The actual calibration process may not be in your general users manual. Askthe vendor to give you the technical application manual, or appropriatepages, for calibrating sensors and actuators.

Generally, sensor calibration can be accomplished by facility staff. How-ever, you may wish to have your vendor assist in calibrating some or all of

Are YouCalibrated?

Answer the following questions todetermine if your system orequipment needs calibration:

1. Are you sure your sensors andactuators were calibratedwhen originally installed?

2. Have your sensors or actuatorsbeen calibrated sinceinstallation?

3. Were you dissatisfied with yourcontrols installation?

4. Have temperature complaintscome from areas that ought tobe comfortable?

5. Are any systems performingerratically?

6. Do sensors experience erraticeffects due to their location?If so, have these effects beenidentified, corrected, orcompensated for?

7. Are there areas or equipmentthat repeatedly have comfort oroperational problems?

5-11

OPTIMIZATION

the actuators. General calibration procedures and tolerances are found inthe Commissioning section of Appendix A: Sample Control SpecificationLanguage. Start with the systems that are having comfort or operationalproblems. Calibration is more critical to sensors used for control than tothose used for monitoring or diagnostics. For example, an air handler dis-charge flow station that may be used for monitoring but has no controlresponsibilities is less critical than the discharge air temperature sensor.Likewise, a discharge duct static pressure sensor used only as a high-limitsafety need not be as precisely calibrated as the sensor downstream con-trolling the fan speed.

The following is a list of sensors and actuators that will most needcalibration:

• Outside air temperature

• Mixed air temperature

• Return air temperature

• Discharge or supply air temperature

• Coil face discharge air temperature

• Chilled water supply temperature

• Condenser entering water temperature

• Heating water supply temperature

• Wet bulb temperature or RH sensors

• Space temperature sensors

• Economizer and related dampers

• Cooling and heating coil valves

• Static pressure transmitters

• Air and water flow rates (where economically feasible)

• Mixing valves

• Terminal unit dampers and flows

If necessary, set up a maintenance plan to ensure that the system remainscalibrated. Refer to the Calibration section of Appendix A and to the initialcontrols checkout section of Chapter 2: Specifying and Selecting a NewEnergy Management System, for further procedural details.

Functional TestingIdeally, optimization strategies should only be carried out on systems thatare fully functional relative to the current written sequences of operationand control. Functional testing is the procedure of verifying that your equip-ment is operating according to the written control sequences. Functionallytesting your equipment could, in itself, be considered part of optimizingyour system.

Functional testing should follow calibration of sensors and actuators be-cause it frequently relies on EMS readouts for verifying system operationand sensor and actuator values. Functional testing is accomplished by mak-ing a change in a setpoint or physical condition, watching the system re-spond accordingly, and comparing the results to the written sequences. For

Cautions WhenTesting

• Make sure that you don’t causediscomfort for tenants.

• Make sure you don’t take thesystem into dangerous rangeswhere equipment or safety maybe jeopardized.

• Remember to return conditions(setpoints, etc.) to normal aftertesting.

5-12

CHAPTER 5

example, you may wish to functionally test a supply chilled water resetstrategy that resets the supply water setpoint between 42ºF and 48ºF whenthe outside air temperature ranges from 90ºF to 60ºF. Part of the test couldbe to overwrite the outside air sensor to be 90ºF and then observe thesupply water temperature setpoint and the water temperature itself changeto 42ºF on the EMS screen.

The easiest way to functionally test equipment is to start with the sequencesof operation. Go through each paragraph one line at a time. Think abouthow you can cause the system to move through the sequence described,perhaps by overwriting a sensor value in the EMS or changing a setpoint.For example, to put a VAV box into full cooling and observe the airflowincrease, you can either overwrite the space temperature to be much warmerthan the setpoint or lower the setpoint. Changing the schedules may alsobe required to observe startup and unoccupied operation of equipment.

Be sure to document your test procedures and your results—and don’tforget to return the system back to normal after changing any setpoints orschedules.

If you find that the actual sequences do not match the written sequences,make sure you are looking at the latest version of the sequences. Fre-quently, the sequences listed in the control drawings have subtle differ-ences from those in the earlier project specifications of the design engineer.Next, review the actual program code, asking for help from your controlsvendor if necessary.

Another way to functionally test equipment is to use the trending capabili-ties of your EMS or portable dataloggers. Many energy management sys-tems have real-time monitoring features that allow you to observe the valueof monitored parameters graphically onscreen. Trending and monitoringare covered in more detail in Chapter 6: Using EMS for Operational Diag-nostics.

Often, written sequences do not list all conditions or modes. You may haveto develop your own sequences from what you know or surmise aboutoperation during certain conditions such as alarms or equipment failures.Full functional testing will observe the equipment operating through a rangeof conditions from startup, shutdown, low load, high load, alarm condi-tions, etc.

Functionally testing all control sequences may require more time and re-sources than are available. Prioritize your efforts and develop a plan to testthe systems over time. Start with those systems that are the most trouble-some, the most critical, or that use the most energy. Lastly, be sure toupdate your written sequences with clarifications and corrections identifiedduring testing.

Additional information on functional testing is found in the Functional Test-ing section of Chapter 3: Commissioning New Energy Management Systems,and in the Manual Testing section of Chapter 6: Using EMS for OperationalDiagnostics.

Initiating aSystem Response

There are a number of ways tocause responses in the system inorder to simulate a sequence ofoperation:

• Overwrite a sensor value(overwrite the outside airtemperature to be 55ºF, insteadof its actual 75ºF)

• Change a setpoint (change thestatic pressure setpoint from1.2" to 1.7")

• Heat or cool a sensor (apply aheat gun or your hand to azone sensor to initiate a callfor cooling)

• Change a schedule (change thetime the occupied period startsto be earlier in the morning tocapture needed coolerconditions)

• Manually shut equipment off(flip the disconnect on the leadcooling tower fan to see thestandby start)

5-13

OPTIMIZATION

Moving Beyond BasicEnergy Control

In this section, we will discuss ways to improve upon your existing controlstrategies. This optimization information may also be helpful when specify-ing a new EMS or an upgrade to an existing EMS. The strategies discussedhere are currently used in many facilities today.

How Much Control Is Enough?Many of the DDC controllers and advanced EMS available today can beexpanded to control every piece of equipment in the building, including allpumps, fans, valves, dampers, compressors, lighting controls, and more.An important consideration in setup is that of how much control is wanted,needed, or affordable. Each controlled or monitored point must be in-stalled, configured, and tested. The cost of upgrading or replacing an EMSis directly proportional to the number of points installed.

A common practice when installing or upgrading EMS is to reduce thenumber of controlled points to meet budget requirements. When capitalbudget is tight, owners often plan to add points in the future when morecapital is available. However, once funds are available, the need for controlat various levels should be examined.

For example, a small 1/15 hp domestic hot water circulating pump onlyneeds to run when the building is occupied. A separate control point toallow the pump to be scheduled will save little, if any, energy over justwiring it in series to come on when the main air handler comes on. Sched-uling control of the pump would be unnecessary control. On the otherhand, tying small chilled-water coil circulating pumps directly to the chillerbecause they only need to run when the chiller is on (thus eliminating acontrol point), would result in inadequate control. During a freeze shut-down condition, the coils may be damaged unless the control system cancontrol the pumps to run during the freeze condition.

Energy and Demand ControlEnergy costs money. To enhance the investment you have made in yourEMS, use it to reduce energy consumption and demand charges in yourbuilding. This can be accomplished through a wide variety of strategies,some simple, some complex. Energy reduction strategies usually involvechanging setpoints and/or using special software routines. Some strategiesare standard options on many EMS; others must be custom-programmed.

Reducing energy consumption also reduces pollution. For every unit ofenergy use avoided, a unit of pollution is not generated. The environmen-tal benefits are most pronounced for electricity generated at coal-burningplants. Up to two-thirds of the energy sent from the electric plant is typi-cally lost in transmission. Therefore, the reduced electricity use onsite cansignificantly reduce consumption of generating resources. Pollution pre-vention through energy savings is environmentally responsible planning.

DevelopingStrategies forBuildingOptimization

For those facility managers and

building operators who have

taken advantage of all of the

features of their EMS,

optimization is the next step.

“Optimization” is a general term

that could be applied to a piece

of equipment, a building system

or the entire facility. The

purpose of an optimization

strategy is to deliver and

maintain visual, acoustic and

thermal comfort in the building

in the most efficient and reliable

manner possible.

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CHAPTER 5

Scheduling• Holiday scheduling• Zonal scheduling• Override control and tenant

billing• Night setup/setback• Optimum start• Optimum stop• Morning warm-up/cool-down

Ventilation Control• Carbon dioxide• Occupancy sensors• Supply air volume/OSA damper

compensation routines• Exhaust fans

Air-Side Economizers• Typical air-side• Night ventilation purge

Resets• Supply air/discharge air

temperature• Hot deck and cold deck temperature• Mixed air temperature• Heating water temperature• Entering condenser water

temperature• Chilled water supply temperature• VAV fan duct pressure and flow• Chilled water pressure

Lockouts• Boiler system• Chiller system• Direct expansion compressor

cooling• Resistence heat

Energy Monitoring• Whole building or end-use• kWh or demand

Miscellaneous• Simultaneous heating/cooling

control• Zone-based HVAC control• Dual duct deck control• Chiller staging• Boiler control• Building space pressure• Variable speed drive control• Heat recovery

Lighting• Lighting sweep• Occupancy sensors• Daylight dimming• Zonal lighting control

Demand Control• Demand limiting or load shedding• Sequential startup of equipment• Duty cycling

Table 5-1 lists selected control strategies that can save energy or reducedemand. Many of the strategies require only setpoint changes to currentprogramming, others may require some control programming. Each strat-egy consists of setpoints, parameters and sequences that will ultimatelydetermine how successful the strategy is for saving energy or improvingbuilding control. Often, energy saving strategies are nominally incorpo-rated, but because of faulty sequence logic or ineffective parameters, thestrategy does not meet its potential. For example, resetting the enteringcondenser water temperature setpoint from the cooling tower to be equalto the outside air dry bulb temperature is not nearly as effective as settingit equal to the outdoor wet bulb plus five degrees. Question your designengineer, energy consultant, or reference materials about the most effectivesettings for each strategy used. Following the table are additional detailsdescribing each strategy.

TABLE 5-1.Selected Energy-Conserving Control Strategies

Scheduling

Holiday Scheduling. EMS software will typically provide for holiday sched-ules. These schedules could be as simple as a full-day shutdown at setbacklevels (such as a typical weekend day) or could be a partial shutdown ofthe facility for various hours of the day. Holiday schedules can be pro-grammed a year or more in advance, often for 26 or more special holidayschedules. Each holiday can be designated as a single date or a range ofdates for extended shutdowns. This feature reduces unnecessary energyuse on unoccupied dates.

5-15

OPTIMIZATION

Zonal Scheduling. Zonal scheduling refers to controlling HVAC system atthe zone level with schedules, so that unoccupied areas can be shut down.Ideally, this means that when a space is unoccupied, the dampers of theterminal units go past minimum to shut. The zone terminals do not open(except to maintain a low or high limit) until the zone is occupied (con-trolled by occupancy sensors or tied to light switches, etc.). This savesenergy during generally occupied periods and greatly saves during after-hours overrides.

Override Control and Tenant Billing. When tenants need to work inthe building outside of normal schedules, manual override is oftenused to obtain heating, ventilating, or air-conditioning. This featureallows the operator to take control of any piece of equipment asneeded. Override of automatic control may also be needed at timesof testing, equipment malfunction, or as part of a problem-solvingeffort.

An increasingly popular override feature enables the occupant todial into the system and request heating, cooling, lighting, or otherequipment operation. Override could be accomplished for the wholebuilding (gross override) or for part of the building (zone- or block-level override). This feature is desirable when occupant use is widelyvariable and difficult to program as a schedule into the EMS; further-more, the property managers can, for an agreed-upon cost per squarefoot, bill tenants for the off-schedule operational hours they request.The override request can be telephoned in, executed and timed au-tomatically by the EMS, which also computes billing information.

Night Setup/Setback. Most energy management systems have setback andsetup capabilities included and programmed as standard features. This com-monly used strategy changes setpoints during unoccupied hours. The spacetemperature setpoints are reduced in the winter and increased in the sum-mer, reducing energy use. This strategy may save more energy than turningsystems completely off during unoccupied periods, if morning warm-up orcool-down use inefficient energy sources (e.g., resistance heat). However,except in extreme climates, most setup/setback routines are used more as asafety. In these cases, the energy savings strategy is to turn the equipmentoff all night, except in the most extreme weather, when the setup/setbackwill be initiated. For HVAC systems that use heat pumps, this strategy shouldbe used with caution, especially in winter—the cost of the make-up electricresistance heat often outweighs the energy savings from the setback. Aux-iliary electric resistance heat should be locked out during the warm-upcycle, regardless of system type.

Optimum Start. EMS can provide customized routines for starting up thebuilding in the morning. Starting the equipment only as early as required tobring the building to setpoint at the occupied time yields energy savings.These routines take into account outside temperature and inside space tem-peratures when initiating the morning warm-up or cool-down cycles. This

RequestedA/C

EMS

Bill

HVAC

FIGURE 5-2.Override Control

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CHAPTER 5

strategy is most appropriate for facilities that have unoccupied periods whenthe zones are allowed to go beyond normal temperature comfort limits.

The goal for an optimum start procedure in heating mode is to provide asmuch heating as possible to warm up the building for the least amount ofenergy possible, while avoiding demand spikes and setpoint overshoot.Normal equipment heating operation, when used in building startup, willfrequently produce longer lead-time and wasted energy. Some best prac-tices can be incorporated by using your EMS:

• Close outside air dampers. Also, turn off exhaust or relief fans.

• Open return air dampers. This will facilitate rapid warm-up.

• Open terminal dampers 100% and drive full heat from the central boileror heating plant to air handlers.

• For electrically heated buildings, keep careful tabs on electric energyuse and demand.

• Watch for excessive cooling directly after warm-up sequences.

• Carefully evaluate shutting down or having large setbacks or setups withheat pump systems.

Optimum Stop. The optimum stop strategy determines the earliest possibletime to turn off equipment before unoccupied periods and still maintainoccupant comfort. This is known as “coasting.” Some equipment may beturned off in the afternoon while the building is still occupied. However, itis important to carefully evaluate shutting down equipment (fans, etc.) thatprovides ventilation for occupants.

Morning Warm-Up/Cool-Down. On days of extreme temperature, the great-est daily demand for heating or cooling may occur in the morning as thebuilding is prepared for occupancy. Nighttime conditions due to equip-ment scheduling and setbacks for unoccupied hours will necessitate a sig-nificant and rapid change in temperature. Usually, these cycles are basictime-clock functions with some interlocks. The optimization of the warm-up sequence is covered in the “Optimum Start” topic above.

Ventilation ControlNonresidential buildings require a minimum amount of outside air for ven-tilation. Depending on the function of the building, this requirement isapproximately 15 to 40 cubic feet per minute (CFM) per occupant. In somebuildings, such as hospitals and laboratories, there is a need for 100%outside air supply. Earlier methods, which set the outside air dampers’minimum position as a fixed value, will not maintain a constant supply offresh air in VAV systems, as the terminal units turn down during heating orperiods of low cooling load. Consequently, strategies that allow variablecontrol of minimum outside air damper position are used. A few of theavailable strategies are provided below, as well as information on control-ling exhaust fans.

5-17

OPTIMIZATION

Carbon Dioxide Monitoring. In this strategy, the CO2 level is generallyused as an indicator of the number of occupants, as CO2 is not itself adangerous contaminant. Calculations are used to relate the CO2 level to thefresh outside air, in CFM per person, being provided to the space. CO2

monitors are typically placed in the return air stream. When the CO2 levelrises to a predetermined threshold, outside air dampers open further toincrease the outside air volume. Outside Air

Damper

CO2Sensor Return Air

EMS

Supply Air HVAC

FIGURE 5-3.CO2 Monitoring

Supply Air Volume/Outside Air Damper Compensation Routines. Accord-ing to a schedule set up by the air balancer, this strategy increases theoutside air damper minimum setting as the supply fan flow decreases (viainlet vanes or variable speed drive) in order to keep the minimum outsideair volume constant.

Flow Sensing Methods. There are a number of outside air flow sensingmethods that can dynamically measure and regulate the minimum outsideair flow using the EMS. One method is to use a pitot tube flow station, ifadequate lengths of straight duct is provided (unfortunately rare) and out-door air velocity doesn’t go below 800 feet per minute. Another method isto maintain a minimum pressure differential across a flow plate in the out-side air intake.

Occupancy Sensors. This strategy detects occupants in a space. When thespace is unoccupied, the lights are turned off and the VAV box minimumairflow is set to zero. This is especially effective in intermittently occupiedspaces such as conference rooms, cafeterias, break rooms, etc. Savingscome from cooling, heating and ventilation reduction. Ideally, the strategyshould be disabled during periods of outside air economizing.

Injection Fans. An EMS can provide control of a dedicated outside air fanthat delivers a constant volume of outside air into the mixed air stream.

Exhaust Fans. Dedicated system exhausts (rest room, mechanical room,garages, meeting rooms, etc.) can be programmed to start and stop as

5-18

CHAPTER 5

required. In parking garages, carbon monoxide sensors can be used to cycleexhaust fans when the levels approach predetermined limits.

Air-Side EconomizingEconomizing, in this context, means the use of cooler outside air to cool abuilding.

Typical Air-Side. Air-side economizing, also known as free cooling, is thepractice of bringing outside air directly into the building to augment or sup-plant mechanical cooling. In this strategy, the EMS compares the outside airconditions with either the inside conditions or a preset condition or setpoint.When outside air will benefit cooling, the outside air dampers open to maxi-mum or to meet a mixed or supply air temperature minimum setpoint. Thesimplest method is dry-bulb economizing and examines dry-bulb tempera-tures only. In concept, a more efficient method is to compare enthalpy (totalheat content of the air, including moisture). However, the enthalpy sensorsmay require more maintenance and calibration.

Night Ventilation Purge. For climates with a large nighttime temperature drops(dry climates), purging or flushing the building with cool outside air in theearly morning hours, with supply fans in economizer mode, can reduce thecooling load in the building later in the morning and save energy. Whenimplementing this strategy, investigate whether the cooling energy savingsoutweigh the increased fan energy and fan heat penalty (for dry climates thisusually means not purging until the outside air temperature is at least 6ºFbelow inside air).

ResetsReset routines are among the most common and most effective energy-sav-ing practices for EMS. The logic and calculation power of DDC allows formore than just the simple proportional reset strategies of the past to beincorporated. Polling numerous point values and using them to make calcu-lations for optimized reset routines can easily be accomplished with DDC.

The intent of a reset strategy is to identify changes in demand (cooling,heating, pressure, flow rate) and reset delivery of air or water to meet thatdemand. This is accomplished by monitoring the control point in question(e.g., discharge air temperature) and several other parameters that impactthat point (e.g., return air temperature, outside air temperature). When theseparameters indicate that load is decreasing or increasing, the control pointcan be reset to better fit the current demand.

Supply Air/Discharge Air Temperature. For fan systems that use terminalreheat, resetting the supply air temperature setpoint up as the cooling loaddecreases reduces required reheat. Higher discharge air temperatures canalso increase efficiency of direct expansion compressors. Supply or dischargeair can be reset based on indirect load indicators, such as outside air, but thepreferred method is to base reset on direct indicators of load, such as returnair/supply air temperature difference or cooling coil valve position. Thereare many ways to set up the routine. One method is to raise the discharge

What AreResets?

Reset is the strategy of changing

a control parameter setpoint

based on a change in related

conditions. Temperature and

pressure are the most common

reset parameters.

5-19

OPTIMIZATION

temperature setpoint incrementally until one zone is 1ºF above its deadband.Note the interaction issues in the Reset Interactions section below.

Hot Deck and Cold Deck Temperature. Many HVAC systems utilize a dualduct or multi-zone arrangement with parallel hot and cold decks. Thesesystems meet cooling loads by providing simultaneous heating and cooling.Warm air from the hot deck and cool air from the cold deck must be mixedto deliver the proper temperature of supply air. Without reset or optimiza-tion, these systems are very inefficient, particularly when the deck tempera-tures are fixed. To minimize energy waste, reset the temperatures, decreasingthe differential between the decks. With this strategy, the EMS selects thezones with the greatest demand for heating and cooling. The deck tempera-tures are then set to provide the warmest cold deck and coolest hot deckpossible while still satisfying the extreme zones.

Mixed Air Temperature. Systems with a mixed air temperature setpoint cancontrol the setpoint with a DDC system. By raising the mixed air temperatureabove the typical 55ºF maximum when cooling loads in the building are low,the periods of free cooling (economizing) are maximized.

Heating Water Temperature. For hot water heating systems, the hot watersupply temperature can be reduced as the heating requirements for the build-ing are reduced. The most common form of hot water reset is to recalculatethe hot water supply temperature setpoint as a function of outside air, anindirect load indicator. A preferable method is to reset the hot water usingthe supply and return water differential temperature (dT) to determine theactual building load. This is accomplished most effectively with 3-way valves.As the dT drops, the hot water supply temperature is reduced until the dTincreases to a predetermined differential, or until a minimum hot water sup-ply temperature (based on outside air temperature) is reached. Another load-based method is to reset the heating water temperature setpoint downincrementally until one heating valve is 100% open. Note the interactionissues in the Reset Interactions section below.

VAV Fan Duct Pressure and Flow. Resetting VAV airflow or static pressuredown during periods of low cooling load reduces unnecessary fan energy.Traditional VAV fan control strategies use a fixed duct static pressure setpointcontrol that is independent of actual airflow requirements at the terminalunits. With DDC data coming back from the terminal units in the form ofdamper position or airflow, the supply fan can be incrementally sloweddown using a variable speed drive (or closed inlet vanes) to maintain oneterminal box at 100% of design flow. This makes the fan run as slowly aspossible while still keeping all boxes satisfied. Implementation methods vary:some reset the duct static pressure setpoint downward to meet the criteria;others bypass this intermediate calculation and go directly to the fan speedor inlet vane controller and simply reduce flow, without any duct static pres-sure setpoint.

In addition to load-related reset, other opportunities are available when ad-dressing outside air requirements. In most VAV systems, each VAV box is

5-20

CHAPTER 5

assigned a minimum airflow setpoint, designed to ensure adequate outsideairflow for maintenance of indoor air quality and usually kept constant overtime. However, the box may deliver excess fresh air at the minimum airflowsetpoint, depending on the outside air fraction in the supply air. Energysaving optimization would recalculate the box minimum airflow setpointperiodically throughout operation. This reset strategy and the calculation ofpercent outside air may involve direct measurement of outside airflow.Note the interaction issues in the Reset Interactions section below.

Variable Inlet Vanes orVariable Frequency Drive

Damper

OutsideAir

ExhaustAir

Damper

Return FanReturnAir

SupplyAir

Supply FanFilter Unit

Preheat Coil

Humidifier

Cooling Coil To VAVBoxes

FIGURE 5-4.Variable Air Volume System Schematic

Entering Condenser Water Temperature. Resetting the chiller entering con-denser water to a lower value will save energy by increasing chiller effi-ciency. When outside air wet bulb temperatures are high enough that lowercondenser water temperatures cannot be achieved, increasing cooling towerfan stages would be of no benefit. Therefore, make the attainable con-denser water temperature the setpoint for controlling fans. This is typicallyequal to the outside air web bulb plus 5 to 10 degrees (the cooling towerapproach temperature). This is subject to a minimum of usually 60 to 70degrees entering condenser water temperature or a minimum pressure ortemperature differential in the chiller, depending on chiller limitations.

Chilled Water Supply Temperature. For chilled water systems, the chilledwater loop temperature can be raised as the cooling requirements for thebuilding are reduced, increasing chiller efficiency. As with hot water reset,the typical variable for reset calculation is outside air. However, direct load-related parameters, such as supply and return water temperature differenceor chilled water valve position, are preferable. A typical method of load

5-21

OPTIMIZATION

reset is to raise the chilled water temperature setpoint until one chilledwater valve is 100% open, subject to any special space humidity require-ments that would require the chilled water temperature to remain at itsminimum.

Chilled water reset is most effective when the chiller horsepower is morethan three or four times the horsepower of the chilled water pumps. Underthese conditions, the decrease in power drawn by the chiller will more thancompensate for any additional chilled water pumping requirements due tohigher chilled water temperatures. Note the interaction issues in the ResetInteractions section below.

Chilled Water Secondary Loop Pressure. Instead of controlling the second-ary chilled water loop to a fixed differential pressure setpoint under allconditions, this strategy resets the pressure down as the load decreases (thechilled water valves close) to always have one cooling coil valve 100% open.This keeps the pumps operating at the very lowest pressure and speedpossible. Note the interaction issues in the Reset Interactions section below.

Heating Water Secondary Loop Pressure. This strategy is the analogous tothe one for chilled water systems.

Reset Interactions. There can be significant interactions among some of thereset strategies. For example, for a given load condition, when the chilledwater supply temperature is reset up, the chiller efficiency is improved. Butwhere warmer water is sent to the cooling coils, the cooling coil valves openfurther and call for more water, thus increasing the pumping speed andenergy. In this case, saving chiller energy is done at the expense of increas-ing pump energy. A hand calculation has been made which shows thatnormally the pump energy per ton of cooling is greater than the chillerenergy. Therefore, the ideal strategy would be to continue to reset the pumpspeed down as load decreases until the pumps reach their minimum safeflow (10-30%), then hold them constant and start to raise the chilled watersetpoint, if the load is still decreasing.

A similar problem exists with VAV duct static pressure reset and supply airreset. When employing both strategies, reduce duct static pressure to itsminimum, and then begin resetting the supply air temperature up, if there islittle terminal reheat. If there is significant reheat, reset supply air tempera-ture up first. These methods can easily be programmed using DDC.

LockoutsLockouts are used to ensure that equipment does not come on at a pointwhen it is rarely, if ever, needed. This protects against nuances in the con-trol system programming that may cause the equipment to turn on unneces-sarily. When locking out a major piece of equipment, remember to also lockout any other associated equipment that doesn’t need to be on.

Boiler System. The boiler and associated pumps can be locked out above aset outside air temperature, by calendar date, or when building heatingrequirements are below a minimum (see Heating Water Temperature above).

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CHAPTER 5

Chiller System. The chiller and associated pumps can be locked out belowa set outside air temperature, by calendar date, or when building coolingrequirements are below a minimum.

DX Compressor Cooling. Lock out direct expansion (DX) cooling whenoutside air conditions will allow economizer operation to meet the coolingloads. This should be subject to any relative humidity control that mayrequire dehumidification with the DX even during economy cycles.

Resistance Heat. Resistance heating is a major source of energy waste insystems. Lock out all resistance heating above a set outside air temperatureand in any warm-up modes, regardless of temperature, when possible. Iflocking out reheat above a set temperature causes overcooling of a space,consider raising the supply air temperature, reducing airflow, or rearrangingdiffusers.

Miscellaneous Strategies

Simultaneous Heating/Cooling Control. An EMS can be used to control andminimize simultaneous heating and cooling for a number of equipmenttypes, including dual duct mixing, VAV boxes, and terminal reheat systems(as discussed in the Resistance Heat section above). This is accomplished bymaintaining wide space temperature deadbands between heating and cool-ing, raising cold deck setpoints and lowering hot deck setpoints, and lock-ing out heating and cooling when appropriate.

Chiller Staging. Most optimization strategies for central cooling plant equip-ment have two elements: staging equipment for maximum efficiency, andresetting output parameters for maximum energy savings. For facilities thatuse multiple chillers, the ideal strategy will determine the total cooling loadon the chiller system, compare the part load efficiencies and capacities of allavailable chillers, and determine the most efficient mix of chillers to haveonline. This strategy is complicated by the need to keep run-times over theyear close to equal and the danger of cycling the chillers so much thatefficiency and equipment life are compromised. Some EMS have standardchiller optimization programs that require minimal programming.

Boiler Control. For facilities that use multiple boilers, some logic must beapplied to determine sequencing. If the boilers are small, of roughly equalsize and efficiency, and have little energy overhead associated with startingand stopping operation, the logic is simple: Add and subtract boilers asnecessary to meet the load. To maximize efficiency in more complex plants,schedule the boilers to give preference to the most efficient boiler andminimize partial loading. In addition, it is sometimes desirable to control theboiler firing mode to increase efficiency.

Building Space Pressure. For VAV air handlers, it is advantageous to monitorand control space pressure. Lab environments often use this sequence tocontrol flow of contaminants, fumes, or lab air. The space pressurizationlevel is maintained by monitoring the pressure and adjusting supply andreturn flows (via dampers, inlet vanes or variable speed drives) in order toachieve the desired pressure.

5-23

OPTIMIZATION

Space pressurization can have effects on both energy use and indoor airquality (IAQ). Unless you have special requirements, the recommendationis to maintain a slightly positive pressure inside the building relative to theoutside. This ensures that no unfiltered or untreated air infiltrates the build-ing and that exterior doors are not hard to open due to a negative pressure.This is especially critical for moisture control in humid climates.

Air-Side Heat Recovery. For systems with a large fraction of outside air orsystems with large auxiliary exhaust fans, heat can be extracted from theexhaust air stream via a coil heat exchanger and a water or glycol loop andtransferred to the incoming cold outside air via heating coils. Heat wheelheat exchangers in the exhaust air stream are also used.

LightingAs the market for lighting products has moved toward energy-efficiency,more and more building owners are implementing lighting retrofits andupgrades, often using EMS controls.

Lighting Sweep. The main energy saving strategy with lighting ON/OFFcontrol is the same as that for other equipment: provide lighting only whenand where it is needed. The simplest way to ensure that lights are turnedoff at night and remain off is to have the EMS periodically “sweep” themoff. For example, the EMS could be programmed to turn off all lights onvarious floors every hour on the hour from 9 pm to 5 am. Ideally, theswitches that allow lights to be turned back on should only control smallzones.

Occupancy Sensors. For advanced control, lighting systems are tied to oc-cupancy sensors and to the EMS to provide information on occupancystatus. Both lighting and HVAC are set back or turned off when the space isunoccupied.

Daylight Dimming. In perimeter zones of the building with sufficient win-dows, the lighting can be dimmed to maintain a minimum light level in thespace. This is best accomplished through continuously dimmable electronicballasts (rather than lowering light output in discreet steps).

Zonal Lighting Control. Reducing the size of lighting zones can save en-ergy by allowing only the occupied zones to be lit, rather than an entirefloor. Savings can be significant in cases where there are smaller groups oftenants who start or end work at different times or frequently come in afternormal occupied hours.

Demand ControlThe goal of demand strategies is to reduce whole-building demand (theparameter upon which demand charge is based), not to reduce individualequipment demand. For example, it is acceptable for one piece of equip-ment to peak heavily in the middle of the night when other equipment isoff and whole-building demand is low. Similarly, at times of peak demand,reducing any demand will contribute to lower demand charges.

Demand ChargesAre Significant

Demand charges can make up

40% or more of a utility bill.

Demand control is a popular

and successful feature of EMS

and a powerful way to provide

integrated control of the whole

building.

5-24

CHAPTER 5

It is wise to review the operation of the EMS demand limiter, especially asbuilding loads and operations change. Also, review conditions when de-mand limiting is invoked. If it is during building startup, an improved startupsequence may be a better option. Exercise caution when implementingdemand strategies. Most of the time, the reason the electric demand is highis that maximum cooling is needed; it may be that you cannot reducedemand without sacrificing comfort.

Demand Limiting or Load Shedding. This strategy can be based on a singleelectric meter, multiple meters, or on equipment current (e.g., chiller). Imple-mentation of demand limiting or shedding varies. Typical methods are:When the demand (based on kW or current amps) on a building meter orpiece of equipment approaches a predetermined setpoint (which may bedifferent for each month), the system will not allow the piece of equipmentto load up any further (e.g., chiller), or it may globally increase the spacetemperature setpoint, or some other setpoint, to stop the increase in equip-ment loading and thus the demand. Some methods increase the space tem-perature setpoint in one or more zones and if that is not sufficient, addother zones.

Another method is to select equipment to shut off, rather than just limit itsloading. Parameters to be set for load shedding control points include:rated kW, minimum shed time, maximum shed time, minimum time be-tween shed, shed type, and shed priority.

There are sophisticated EMS controllers that automatically integrate a de-mand-limiting and load-shedding strategy with utility real-time pricing ratestructures. The control parameter, rather than the static kW demand limit, isthe optimization of the real-time energy cost based on the hourly energyprice.

Sequential Startup of Equipment. To eliminate demand spikes, programtime delays between startup of major electrical load-generating equipmentso that the startup peak loads stay below the peak demand later in the day.

Energy MonitoringEnergy consumption is an important parameter to track. It is the bottomline for most control strategies and has ramifications to maintenance needsas well. Whole-building annual kWh per square foot is a useful metric forcomparison with other similar buildings. However, energy consumption israrely monitored by EMS, other than possibly chiller kW, or total buildingor system kW for buildings with significant demand limiting. For monitoredsystems, the following may be tracked:

• kWh consumption and demand

• Time the peak occurred

• Selected demand limit

• Natural gas consumption

• Steam consumption and flow

• Time that any load was shed

Types of DemandPoints

The operator can specify a control

point as one of several kinds of

demand points:

• “Round-robin” demand point:designated first off/first on,second off/second on, and soon.

• “Priority” demand point:designated first off/last on.

• “Temperature” demand point:shed such that the load closest

to the setpoint is shed first.

5-25

OPTIMIZATION

For energy performance projects, kWh may be monitored for other equip-ment as well, including minimum, maximum, and average outside air tem-peratures (OSAT) and outside environmental information. In addition, it isuseful to plot energy consumption versus different driving factors, such asOSAT, occupancy, or production.

Direct monitoring of energy consumption is difficult because of the initialsetup required; the use of proxies may be more feasible and answer thesame energy use questions. For example, monitor run-time for pumpsrather than energy consumption, or variable frequency drive control signalrather than energy consumption.

Energy monitoring even a few major end-uses can greatly improve tradi-tional monthly energy accounting. The uncertainty involved in using en-ergy accounting software packages will be reduced if additional end-usedata are available. The EMS can add critical information on major end-usesto the picture and allow for usable and reliable energy accounting recom-mendations.

Performance Contracts. EMS energy and performance monitoring capa-bilities can be utilized in energy performance contracts. The EMS can de-termine and document baseline conditions (hours of operation andoccupancy, equipment efficiencies, etc.) and verify post-installation per-formance by aiding in commissioning and operations tracking. The EMScan also be instrumented to calculate and track weather conditions (de-gree days, etc.) and correlate that with whole building or end-use (equip-ment) energy consumption tracked in the EMS.

Optimization Example:Savings from Basic EMSEnergy management systems are of-ten installed or upgraded as capitalprojects designed to save energy cost-effectively. In some cases, the sav-ings will come from the more basicfunctions of the EMS, as demonstratedby the following example.

A bowling alley owner purchased asmall EMS for the advanced tempera-ture control technology, but did notexpect significant additional savings.The building uses 11 rooftop heatpumps and packaged air-condition-ing units for a total of 75 tons of cooling. The EMS was installed to controlthe heating and cooling equipment as well as the lighting and signs. Throughbasic scheduling and temperature control, along with optimum start rou-tines, the bowling alley achieved significant energy savings as demon-strated in Figure 5-5.

1 2 3 4 5 6 7 8 9 10 11 12

90,000

85,000

80,000

75,000

70,000

65,000

60,000

55,000

50,000

45,000

40,000

Ener

gy C

onsu

mpt

ion

(kW

h)

Month

kWh Before

kWh After

Installation Price: $9375First-Year Savings: $4254

FIGURE 5-5.Energy Reduction Through EMS: Bowling Alley

5-26

CHAPTER 5

Underwriter’s Laboratory Project:Savings from More Advanced EMS FeaturesThis example demonstrates how the more advanced features of EMS can beused to the fullest to obtain energy savings, comfort, and reliability. TheUnderwriter’s Laboratory (UL) facility is located in Camas, Washington. Itconsists of a two-story building with approximately 112,800 square feet ofconditioned space. Facility use includes a mix of office space, testing labo-ratories, and storage space. Fuel use consists of electricity for most end-uses with natural gas for heating.

The energy management system for the UL facility is responsible for imple-menting and managing a variety of energy conservation strategies:

Direct digital control of controlled devices. In this building, tight DDC al-lowed the space temperature heating setpoints to be lowered by one de-gree and the space temperature cooling setpoints to be raised by one degree,resulting in significant energy savings.

Optimized supply air reset control. The DDC system’s ability to collectinformation from every zone allowed the primary supply air temperature tobe reset based on a signal from the zone with the greatest cooling load.This saves energy by reducing reheat and improving plant efficiency.

Optimum fan start control. Fans are started to adjust morning warm-up orcool-down periods to be the shortest possible and still maintain space tem-perature setpoints by the beginning of the occupied period.

Centralized scheduling of all fans, pumps, and HVAC equipment. Central-ized scheduling of equipment achieves energy savings from less occupantadjustment of space temperature setpoints and more consistent and sensi-tive ON/OFF scheduling of equipment. For example, fan operating hourshave been reduced by about 5 hours per week.

Chilled and heating water supply temperature reset control. For this strat-egy, chilled water temperatures are reset to the highest temperature thatcan still meet cooling loads. Energy savings are accomplished by increasingchiller operating efficiency, decreasing reheat energy, and reducing heatgain through piping. Also, heating water temperature will reset to the low-est temperature that can still meet heating loads. Energy savings are accom-plished by reducing heat loss through the boiler and piping.

Morning warm-up period control of outside air dampers. This control strat-egy keeps the outside air dampers closed when the HVAC systems areoperating to bring the building “up to temperature.” Energy savings areachieved by not conditioning outside air during the morning period beforeoccupants arrive.

Scheduled lighting “sweep” control. During unoccupied periods, the EMSsends timed pulses to low-voltage relays in the lighting circuits, turning offthe lights on any particular circuit. Occupant override stations are installedfor individual lighting circuits.

AnnualSavings

This system’s energy-saving

control strategies yield

significantly more savings than

an older prepneumatic or

manual system could achieve:

Annual Energy Savings

• 273,750 kWh

• 21,4000 therms

Annual Cost Savings

• $17,211

(15¢ per square foot)

5-27

OPTIMIZATION

Further Resources

American Society of Heating, Refrigeration, and Air-conditioning Engineers(800/527-4723), “Automatic Control,” ASHRAE Applications, 1995

American Society of Heating, Refrigeration, and Air-conditioning Engineers(800/527-4723), “Building Operating Dynamics and Strategies,” ASHRAE Ap-plications, 1995

American Society of Heating, Refrigeration, and Air-conditioning Engineers(800/527-4723), “Optimal Control Strategies,” Collected from ASHRAE Win-ter Meeting, 1993

Cratty and Williams, “Energy Management Control Systems,” from Energy Man-agement Handbook, The Fairmont Press (770/925-9558), 1992

Grimm and Rosaler, Handbook of HVAC Design, McGraw Hill (800/2-MCGRAW), 1990

Gupton, G., HVAC Controls: Operation and Maintenance, The Fairmont Press(770/925-9558), 1996

McGowan, J., Direct Digital Control: a Guide to Building Automation, TheFairmont Press (770/925-9558), 1995

Monger, S., HVAC Systems: Operation, Maintenance, and Optimization, PrenticeHall (800/223-2348), 1992

National Electrical Contractors Association and Edison Electric Institute (301/657-3110), Energy for the Year 2000: a Total Energy Management Handbook,1997

Thumann, A., Optimizing HVAC Systems, The Fairmont Press (770/925-9558),1988

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CHAPTER 5

C H A P T E R

Diagnostics are EMS features that assess how equipment and systemsare working and identify problems or opportunities for improvement.

Diagnostics can help you investigate control loops and verify their opera-tion, learn more about your building, and ensure that efficient equipmentoperation continues as expected. This chapter will describe two primarymethods of using EMS for diagnostics: Trending and Manual Testing. A re-lated topic, Maintenance Control, is discussed in Chapter 7: Non-Energy ControlApplications.

Before you can confidently use your EMS system for diagnostics, all sensorsand actuators must be calibrated so that you can depend on the values andconditions reported by the trends. Calibration is covered in Chapter 5: Strat-egies for Optimization.

Trending

Basic trending and monitoring was described in Chapter 5. This section con-tains a more in-depth description of trending features and their use. Yourcurrent system may already have a number of trending features; but softwareor even a hardware upgrade may be required to obtain all the features youneed. Because details and instructions on trending capabilities and methodsare not always found in O&M manuals, you may need to contact your ven-dor to determine your system’s features and how to use them. Read themanual, call the vendor for help, set up a few trends, and then analyze thedata in a couple of different ways to become familiar with this feature.

Trend logging capabilities vary considerably among EMS systems. The extentof these capabilities in your system will, to a great degree, determine whethertrending can reasonably be used for diagnostics. Review the list of trendlogging capabilities in Appendix A: Sample Control Specification Language,and determine which of them your system can employ.

Planning and Setting Up Trends

The first step in setting up a trend is to develop a trending plan: the points to betrended; the value type to be trended; the sampling rate; the trend group eachpoint will be analyzed with; and the visual method of analysis to be used.

Using EMS forOperational DiagnosticsMethods and techniques

72.5

Trend Dataand Diagnostics

Trend data—snapshots of recent

operational history in your

building—are an excellent tool

for diagnostics. Traditionally,

alarms (rather than trend

graphs) have been used to notify

the operator of problems.

However, alarms are usually

intended for fault detection rather

than for diagnostics.

6-2

CHAPTER 6

To decide which parameters to trend, study the control drawings and thewritten sequence of operations. There are hundreds of trends that could beappropriate for your facility. Table 6-1 provides a small set of possibletrends.

Trend Types. There are two trend types—value stream and change of value(COV). A value stream trend takes a reading of the point value (tempera-ture, pressure, etc.) at each sampling interval. A COV trend records only ata pre-specified change in value or status. COV trends use less cabinet memoryand are easier to follow on columnar printouts. However, the COV presetchange amount must be carefully defined or resolution may be lost.

For ON/OFF status of equipment, consider using a COV trend. To graphON/OFF values for illustration purposes, use a data stream trend. Also,generally use data stream trends for parameters that have changing values,like temperatures, pressures, voltages, controllers, etc. When trending anumber of parameters by COV (10 or more), do not mix the COV param-eters with the data stream parameters in setting up the trend or merge themat downloading. That would result in large data-stream gaps and difficultgraphing and analysis. Generate the two types of parameters as differentfiles and combine them later in the spreadsheet graph, if desired.

Trending the status of points and analyzing status requires some thought.An ON status simply indicates that the software has calculated that thedevice should be ON, without giving the reason why—e.g., overriding, astuck relay, short cycle protection, etc. Depending on the goal of the trend-ing, these other factors may need to be taken into account. Likewise trend-ing a valve position command does not guarantee that the valve is actuallyat the commanded position. Calibration before trending may be required.(See the Calibration section in Chapter 5: Strategies for Optimization.)

Some systems automatically generate reports called Scheduled and ProcessStart and Stop. The information for these reports is always being generatedin the background. All it takes is a call for the report by system (e.g., AHU-3), to obtain the date, time, event (command ON or OFF), status of the unit(normal, override) and the reason for the change in status (schedule, aprocess, manual command, etc.). Other such useful reports may be avail-able in your EMS.

Many EMS will continually trend a point for the last 24 hours, if this optionis simply selected in a “point history” menu. At any time, the point historycan be called up and viewed graphically onscreen. This tool can be veryvaluable.

Sampling Rates. The proper sampling rate depends on the purpose of thetrend, the type of equipment being monitored, and the memory limitationsof the EMS system. The number of points an EMS can sample instanta-neously may be limited, so that trending a large number of points simulta-neously (e.g., 100) can lead to discontinuous data and problematic analysis.

What ToTrend

Trending may be prioritized in

the following order:

1. Systems or areas with current

comfort or operational

problems

2. Systems suspected of faulty

functioning

3. Systems that tend to have

problems, such as

economizers, variable speed

drives, etc.

4. Systems that consume large

amounts of energy, such as

chiller systems, air handler

units and lighting

5. Systems that have recently

been repaired or retrofittedand need operational

verification

6-3

DIAGNOSTICS

TABLE 6-1.Sample Trends

Identify unnecessaryequipment operation(chillers, air handlers,pumps, exhaust fans,lights, etc.)

Change of value (COV), anotherindicator or an ON condition.Time-series also works well.

COV or time-series 15 min.

Make sure HVAC is not unnecessarily ON outside ofoccupancy periods. Verify that lighting ON times matchHVAC.

Chiller start Turn ON parameter (cooling coilvalve position, outside airtemperature (OSAT), etc.)

15 min. Make sure chiller is not ON unless the parameterrequirement is met.

Chiller loading Chiller current, OSAT 15 min. Make sure the chiller current draw goes up with OSAT.

Chilled water reset Chilled water supply temperature,reset parameter (OSAT, valveposition, etc.)

15 min. Graph chilled water supply temperature (CHWST) againstOSAT or valve position and compare to reset schedule,or analyze columnar data.

Chiller efficiency Primary chilled water andcondenser flow (or values in TABor start-up report), entering andleaving chilled water and chillerkW (or current, if no kW). Forreference, also trend enteringand leaving condenser watertemperatures.

15 min. for 2weeks

Calculate the kW/ton of cooling for all points and addthis column to the data. Plot the kW/ton (Y-axis) againstthe chiller % load. Save this graph as a benchmark.During similar weather the next season, repeat the trendand graph and see if the kW/ton generally remains thesame or is degrading (possibly indicating fouling).Compare, by interpolation, to manufacturer’s kW/tondata.

Tons = 0.0417 x gpm x (CHWRT – CHWST). kW = Volts xAmps x 1.732 x power factor/1000. Get PF from start-up report

Cooling toweroperation (fans,mixing valve andentering condenserreset)

Fan stage, valve position, towersump, entering and leavingcondenser water temperature,reset parameter (OSA WB, DB),fan stage parameter.

5 min. Compare the fan staging with the schedule, compare theentering condenser temperature with its schedule, andcompare valve operation to expected (closed when enteringcondenser water is greater than setpoint).

Simultaneous heatingand cooling

Heating element enable or valveposition, supply temperature,cooling coil valve position

2 min. Make sure that when the cooling coil valve is open, theheating coil is closed.

Supply air reset Supply air temperature, resetparameter (OSAT, zone demand)

2 min. Graph SAT against OSAT or zone demand and compareto reset schedule, or analyze columnar data similarly.

VAV duct staticpressure control

Duct static pressure (and resetparameters if it is reset)

2 min. Observe, for fixed static pressure systems, that the pressureremains the same during the monitoring period and forreset, that the static pressure follows the reset schedule.

Short cycling COV for ON/OFF issues 2 min. View columnar data for analysis.

Hunting 2 min. orCOV

Actuator position or commandor COV

Plot against time and observe hunting.

Terminal unit Zone temperature, heating coilvalve position, air cfm or damperposition, cfm setpoint (forapplicable controllers). OSAT andthe duct static pressure may alsoneed to be trended.

2 min. Plot with two Y-axes for resolution (valve position on rightaxis). Observe that the zone temperature remains within1°F of the deadband range, that the cfm is not over- orundershooting its setpoint or hunting, that the heatingvalve is not hunting and that the cfm is at minimum beforethe heating valve opens, etc.

Compressor staging Compressor stage, OSAT, RAT, SAT 2 min. Observe that the stages are not short cycling, that theminimum ON/OFF times are not violated, and that thestaging is reasonable relative to the causal conditions.

Issue orEquipment Points To Trend Analysis Summary

SamplingInterval

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CHAPTER 6

If the purpose of the trend is to investigate possible hunting of actuators orshort cycling of equipment, the sampling rate should be ideally about 2minutes. Some hunting can be detected using wider intervals up to 30 min-utes, but the intensity of the hunting or cycling may be masked. Figure 6-1illustrates this by comparing discharge air temperature and setpoint from arooftop air conditioner during the same time frame sampled at three differ-ent rates (2, 16 and 32 minutes). Between every two peaks of each over-shoot cycle on the 32-minute sample, there are really two more cycles, asshown in the two-minute sample. The 32-minute sample would indicate ahunting rate of one-half cycle every 30 minutes, while the actual half cycle isonce every 9 minutes (as shown in the 2-minute graph).

Hunting and short cycling can also be detected by using a COV trend of theequipment status, setpoint or parameter value. In such cases, it is importantto set the incremental change at which the EMS will log a new value to besmall enough not to lose resolution and mask some of the cycling.

For trending parameters with a slow rate of significant change, such asspace or outside air temperatures, a 15- to 30-minute sampling rate is gener-ally adequate. Often, however, they must be sampled at a faster rate to beconsistent with other points requiring a smaller time step. For best resultswith ongoing trends, trend data at fairly slow sampling rates, then tempo-rarily increase the frequency when problems or mysterious behavior aredetected.

Grouping Parameters. For trending projects of more than 6 to 8 points,assign each point to a group consisting of points that you want to analyzetogether. All points within a group should ideally have the same samplingrate. Be sure to enter appropriate point descriptors for each trended pointduring setup so they will be identifiable during analysis. It is often helpful togroup together parameters that have the same units or expected range ofvalues to facilitate graphing on the same axes.

Group together into one trend all parameters that you want to view togetheronscreen (unless your EMS can pull points from different trends for simulta-neous viewing).

Large Trends. The “largeness” of a trend (how many points will be moni-tored, sampling frequency, and duration of the trend) is relative to the EMS.For a new system in a 200,000 square foot building, trending over 75 pointsat 6-minute intervals for one week may be considered large. Old systemsmay not be able to handle even a quarter of that amount. Most trend projectsare not large, but for those times when a large-scale trending project isneeded, the following provides some pointers.

Many EMS trends are generated and data initially stored in the control cabi-net from which their points are controlled. The number of points that can betrended overall is limited by total available storage memory of all controlcabinets together. For large data sets, when cabinet memory is at its limit,you may have to assign points in one trend a larger time step (interval) thanpoints in another trend from the same cabinet to reduce the total number of

6-5

DIAGNOSTICS

stored values. For large trends, use COVdata, which require less memory, when-ever possible. Another solution is to addmemory to the control cabinet.

Large trend projects may also strain thecomputer resources of the EMS, resultingin skipped polling, missing data pointsand skipped downloads. This is especiallytrue for EMS that initiate and executetrends from the central computer CPUrather than from the distributed controlcabinet CPUs. One solution is to dividethe large trend projects into two phases,e.g., run a few trend groups one weekand then a few other groups the follow-ing week.

Downloading. It is critical to fully under-stand how your EMS stores and handlestrend data. You must know whether thedata will automatically download to thehard drive when cabinet memory storageis full; whether you must specify when itshould download; or whether it requiresmanual downloading. If your system doesnot download automatically, find out yourvendor’s rule of thumb for calculating thestorage needed for large trends. To setthe frequency of preassigned or manualdownloads, find out how much storageis available in each cabinet and how todetermine when cabinet memory is at itslimit. Learn how to set up a first-in/first-out trend, where a set number of samplesis stored in the cabinet before the olddata is dumped or erased.

Starting Times. Some EMS can schedulestart-and-stop times of trends, while oth-ers begin trending as soon as the trend isdefined. For data to be viewed in columnar format or using the EMS soft-ware graphics, it is not critical that trends start at precisely the same time.For data to be graphed in commercial spreadsheets, identical start timesand time steps are more important. (However, with a little effort, differentstart times and time steps can be accommodated in newer spreadsheets.)

Averaging. Snapshots of a point value (e.g., hourly snapshots of kW) arenot always useful. Some sort of averaging over a time interval, or possiblya record of minimum or maximum values, is needed.

FIGURE 6-1.Effect of Sample Rate on Trend Graph Resolution

52

54

56

58

60

62

64

66

68

70

0:00 1:12 2:24 3:36 4:48 6:00 7:12 8:24 9:36

Discharge Air Temperature Discharge Air Temperature Setpoint

52

54

56

58

60

62

64

66

68

70

0:00 1:12 2:24 3:36 4:48 6:00 7:12 8:24 9:36

52

54

56

58

60

62

64

66

68

70

0:00 1:12 2:24 3:36 4:48 6:00 7:12 8:24 9:36

2-Minute Data

DAT

(F)

DAT

(F)

DAT

(F)

16-Minute Data

32-Minute Data

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CHAPTER 6

Totalization and Counting. Many EMS can total the number of hours apiece of equipment has been operating. This is valuable for preventivemaintenance planning, as explained in Chapter 7: Non-Energy Control Ap-plications. An EMS can also total the number of times the equipment hasturned ON and OFF during a given period. Dividing the number of timesthe equipment turned on by the number of hours the equipment was run-ning (by schedule or by the totalization function), yields the cycling rateper hour. Short cycling and other malfunctions can be easily detected thisway.

Auto-Diagnostics. Not strictly a trending function, but similar, are the auto-diagnostic functions of some equipment controllers. These can be valuablefor predicting problems and for determining causes of malfunctions. Forexample, a particular VAV controller automatically calculates the ratio ofdamper actuator run-time to total controller run-time. Ratios over 5% indi-cate possible problems. The controller also calculates the moving averageflow error of the terminal unit. If this is greater than 10% of the maximumbox CFM rating, there may be a flow sensor or control loop malfunction.The moving average space temperature deviation is also tracked, whichwill immediately indicate a problem. This is all done continuously andautomatically, without any setup of trends. These diagnostic features arebeing expanded to other types of equipment. Ask your vendor about them.

Types of Data Display

There are five ways that data can be viewed by the operator (depending onthe system):

• Columnar display on the EMS computer screen

• Columnar hard copy printout

• Real-time graphical display on the EMS computer screen

• Graphical display in spreadsheets (historical data)

• Real-time graphical display in spreadsheets

Columnar Display on EMS Computer Screen. This view consists of col-umns of data, with time in the left column and columns of different trendedpoints in adjacent columns. This is useful where analysis will be quick andfurther use of the data unlikely. This is a good way to view standing historylogs when troubleshooting new problems without having to set up andanalyze a special trend log or graph. This format provides accurate values,but is not nearly as easy as graphs for following trends and detecting subtlechanges and correlations among parameters.

Columnar Hard Copy Printout. This is a printout of the columnar dataviewed onscreen. It has the advantage of permanence and can be referredto again as needed.

Real-Time Graphical Display on the EMS Computer Screen. Some EMS canshow current trend data (including multiple points) onscreen as a graph.The screen scrolls off, but can still be seen using the MS Windows screen-

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DIAGNOSTICS

control arrows. The scales or ranges for each point can be assigned, butthis screen viewing method is often crude, lacks visible Y-axis scales, andhas low resolution. Still, this method may be useful for analyzing currentissues where the problems can be identified without high resolution. It is agood idea to save or print the graph of any interesting data, as it may bedifficult to reproduce the situation that caused the interesting graph.

Graphical Display in Spreadsheets (historical data). The most versatile wayto view and analyze trend data is to import the data into a commercialspreadsheet program and use its graphing capabilities. This is time-con-suming, and other methods of viewing the data should generally be usedfirst. However, spreadsheets may be the best option for troubleshooting acomplex problem or fine-tuning control loops; they provide good resolu-tion and printed graphs for analysis or for presentations to others. Thespreadsheet graphing process may be cumbersome at first, but the processcan become quite easy with practice. New commercial software for view-ing monitored data is also becoming available and will further simplify thegraphing process. Refer to Appendix B: Using Spreadsheets for Graphingand Analyzing Trend Data, for details on setting up and using spreadsheetgraphing capabilities.

Real-Time Graphical Display in Spreadsheets. Some EMS can set up trendlogs and transfer the data live to a spreadsheet program using dynamic dataexchange (DDE) software. This allows the user to view, real-time, any trenddata desired. It has the advantages of real-time EMS computer screen dis-play plus the versatility of a spreadsheet. Once the trend and DDE are setup, the user can at any time during or after the trend open the spreadsheetand view the historical and current state of the trended variables bothgraphically and in columnar form. Spreadsheets provide clear graphs withfull resolution and have scaling and labeling features allowing for accurateanalysis. For sophisticated users, dynamic optimization routines can be setup using the computational power of the spreadsheet on the trended datato actually send new setpoints back to the EMS.

Analyzing Data

Analysis of data begins with deciding how to display the data. For initialanalysis, view the real-time onscreen graph. If more resolution is needed orif you are fine-tuning a control loop, use spreadsheet graphs. If the outputis limited to columnar viewing, the method of analysis is limited to printingout the data and paging through it to diagnose the system.

It may be difficult to predict at the outset what will be needed; this willbecome clearer as you go along. Consider constructing scatter plots (plot-ting one variable against another). Add points to trends as you uncovermore clues to operation.

Also, think about the stream of values for each point: what should behappening to the point values at different times of the day, in comparisonto the outside air temperature (for example) or to other points being trended?

Reasons forMalfunctions

• Improper setpoints

• Faulty sequences of operation

(programming)

• Hardware malfunction

• Sensors or actuators out of

calibration

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CHAPTER 6

Review the sequence of operations for the system being analyzed and rec-reate what is happening in the trends compared to what the written se-quences say. For instance, when examining a heating water reset sequence,observe both variables in the strategy, e.g., outside air temperature (OSAT)and heating water supply temperature (HWST). You can also trend thesetpoint itself. You should observe that when the OSAT rises, the HWSTdrops. For more accuracy, calculate from the actual reset schedule what theHWST should be for different OSATs and check the HWST in the trend.Better yet, graph HWST against OSAT with OSAT, rather than time, as theX-axis. For sample graphs, see Figures B-2 and B-3 in Appendix B. As thesecond graph shows, the reset strategy is not functioning properly (it isalways 10ºF to 15ºF above the setpoint); this could not be easily detectedfrom the first time-series graph.

Most control loops have bias or deadbands as well as time delays to pre-vent cycling or to save energy. Misunderstanding these parameters can leadto erroneous conclusions. Figure 6-2 represents actual data from a pack-aged rooftop air conditioner with duct static pressure controlled by its pack-aged controller and pressure transducer. The EMS monitored the duct pressurevia the same air line using its own pressure transducer. At first look, it wasthought that the reason duct static pressure setpoint was never met was thatthe packaged unit’s transducer and the EMS transducer were simply not givingthe same value (not calibrated together). On closer inspection, it was foundthat the packaged unit controller had a +/-0.25 in. water gage deadband. Theproblem was not calibration, but too wide a deadband.

FIGURE 6-2.Effect of Large Deadband on Static Pressure

1.1

1.05

1

0.95

0.9

0.85

0.8

0.75

0.7

0.654:48 7:12 9:36 12:00 14:24 16:48 19:12

Duc

t Sta

tic P

ress

ure

(in. w

g)

6-9

DIAGNOSTICS

Documenting the Analysis. Write up your observations and conclusions.This will aid in future review of the problem and avoid unnecessary repeti-tion of the analysis.

Reporting Data. Once a problem has been identified, consider graphingthe most illustrative areas in a spreadsheet graph, if that has not alreadybeen done. Such graphic documentation is convincing and impressive, andmay be helpful to management.

Manual Testing

Using EMS capabilities can improve the speed, reliability, and efficiency ofmanual testing.

Manual testing with EMS uses onscreen control system readouts to verifyperformance of equipment. The EMS is used to change a setpoint or param-eter and cause a reaction in the system of interest. System response can beimmediately observed on the EMS screen. For example, to see if the heatingvalve position is working properly on a VAV box, the zone temperaturesetpoint could be raised 10°F and the response of the heating valve imme-diately observed. As with trending, calibration of all affected sensors andactuators is required before manual testing can rely on the EMS readouts.Refer to the Calibration of Equipment section of Chapter 5: Strategies forOptimization.

Manual testing differs from monitoring or trending in that trending gener-ally looks at the performance of systems over time—after the event. Intrending, the operator must piece together the cause of a given response inthe system whereas in manual testing, the operator deliberately initiates theaction and immediately observes the response. Also, trending alone typi-cally cannot record the extremes of system operation; it is limited to record-ing events under normal external conditions. With manual testing, the systemcan be easily taken to design conditions or tested under any other simu-lated condition. For example, to test an economizer damper, the outside airtemperature, OSAT (or enthalpy if appropriate), could be overwritten dur-ing the cooling mode to be 50°F, simulating a condition good for econo-mizing using the EMS. The damper response could then be observed in theEMS (or visually if damper position is not monitored). Manual testing alsoallows checking of components that may not be observable in the EMS,e.g., damper position, boiler stage, etc.

Simulating desired conditions may be accomplished by changing setpoints,overwriting analog input values, jumpering contacts, closing power discon-nects, changing schedules, and false-loading equipment. Be sure to returnall conditions to normal after testing is complete.

When manual testing, check the system response just above and below thedeadband of the breakpoint. For instance, in the above economizer ex-ample, if the changeover setpoint was 65°F with a 2°F deadband (+/- 1°F),then overwriting the OSAT to be 50°F may verify that the economizer works,but not that it works properly. To do that, the OSAT should be overwritten

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CHAPTER 6

to 63°F to see if the damper opens, and then overwritten to 67°F to see if itcloses. Alternately, change the changeover setpoint rather than overwritingthe OSAT.

Loop Tuning. Becoming familiar with the loop-tuning capabilities of yoursystem can be valuable. The EMS manual or training can help you learnhow and when to tune control loops to improve performance. Many con-trollers have self-tuning or auto-tuning capabilities, but they may not beenabled. Related to loop tuning are features that automatically calibratetheir sensor to a known condition once each day (e.g., flow sensor cali-brates to zero flow during OFF conditions). This, too, must be enabled tofunction. Enhanced loop tuning, particularly of zone-level controllers, willimprove tenant comfort.

Manual Testing/Trending Combination

Manual testing and trending can be combined when necessary. A trend orpoint history log is started and conditions are altered or simulated as in amanual test; the response, however, is not viewed immediately but re-corded in the trend data and studied later. This method is useful for inves-tigating the response to a parameter or condition over time. For example, ifyou wanted to know if the chiller demand limiter was functioning properly,but the load on the chiller was not currently high enough, you could lowerthe EMS demand limit setpoint for a few days and trend the chiller demandlimiting parameter (current or kW) during that period.

What To Test Manually

The rationale of the previous section on trending also applies to manualtesting. The following are some additional areas to consider testing:

• Items in the Table of Sample Trends (Table 6-1) in the previous section

• Air-side economizer functions: Are outside air dampers fully closed dur-ing warm-up? Do economizer dampers open, and return air dampersclose, to maintain discharge air setpoint right at the economizerchangeover point (enthalpy or dry bulb)? Is the enthalpy or dry bulbsensor calibrated? Does the changeover point setting allow the econo-mizer to operate at the highest possible OSAT? Does the economizerstart first, to maintain setpoint with a differential, before compressorcooling starts?

• Variable speed drives: Do the drives ramp up and down with the wateror air pressure and demand, as expected? Does the drive allow the mo-tor to drop to a very low speed when demand and load are at minimum?

• Boiler staging

• Building static pressure control

• Lighting sweep control

• Exterior lighting photocell control

• Equipment interfaces with the EMS (rooftop units, boilers, fire, life, safety,etc.)

6-11

DIAGNOSTICS

Test Documentation

Small diagnostic tests can be designed and executed without prior writtenplanning, but documenting the test itself is important. Notes should be kepton the conditions of the test, what was done to initiate a response and whatthe response was—or you may have to repeat the test to verify your recol-lections.

Longer tests or checkouts warrant a written test plan. For checking the fullsequences of operation for a given system, complete written proceduresare highly recommended. The process of designing and writing out testprocedures may help clarify the problem even before testing is begun; andthe writer’s increased familiarity with the workings of the system may iden-tify other possible problem areas.

Additional information on functional testing is found in the Functional Testingsection of Chapter 3: Commissioning New Energy Management Systems andin the Functional Testing section of Chapter 5: Strategies for Optimization.

Further Resources

Cratty and Williams, “Energy Management Control Systems,” from EnergyManagement Handbook, The Fairmont Press (770/925-9558), 1992

Grimm and Rosaler, Handbook of HVAC Design, McGraw Hill (800/2-MCGRAW), 1990

Gupton, G., HVAC Controls: Operation and Maintenance, The FairmontPress (770/925-9558), 1996

McGowan, J., Direct Digital Controls: a Guide to Building Automation, TheFairmont Press (770/925-9558), 1995

Thumann, A., Optimizing HVAC Systems, The Fairmont Press (770/925-9558),1988

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CHAPTER 6

C H A P T E R

By definition, an energy management system manages energy—this isits primary objective. However, as more powerful systems are devel-

oped and installed, EMS capabilities are expanding to include nontradi-tional functions. In this chapter, we will discuss potential applications beyondthe traditional scope of EMS operations.

Remember that an EMS is, at heart, a computer program. It can processvirtually any information as long as it has the proper sensors and transduc-ers. Its actions are not limited to the traditional tasks of building systems.Non-energy tasks tap the vast potential of energy management systems.

Maintenance Control

Building managers can use the totaling and counting functions of their EMStrending capabilities to construct duty logs. A duty log offers valuable infor-mation about equipment: how much it is used, how much it is cycling, howwell it is following assigned schedules, and more. With such a log, mainte-nance personnel can more readily determine if maintenance is due or ifequipment needs preventive repair or replacement.

As discussed in Chapters 5 and 6, DDC systems can track and displayinformation such as last time ON/OFF, daily equipment run-times, moni-tored data from analog inputs, energy use, and hardware performance.DDC systems can also accumulate and display monthly scheduled and un-scheduled run-times for each piece of equipment controlled or monitored.Duty logs could show change-of-state for major loads for review on a dailybasis if desired.

For equipment driven by motors, run-time is the basis for scheduling preven-tive maintenance. For filters and heat exchangers, pressure drop is the basis forscheduling maintenance. System operators can assist maintenance personnelby preprogramming instructions that associate maintenance schedules withequipment and report skill levels and tools needed for maintenance tasks.Furthermore, automatic sequencing can be used to equalize run-times. For ex-ample, with a lead-and-lag pumping arrangement, the lead pump can automaticallybe switched once per month (or other interval) to equalize run-time.

Non-Energy ControlApplicationsUsing EMS to capture non-energy benefits—some innovative examples.

What Is a“Non-Energy”Application?

•One that does not have a direct

impact on energy use—although

it might have an indirect effect.

•One that will produce non-

energy benefits such as

increased worker productivity

or production efficiency.

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CHAPTER 7

Some EMS have complete add-on computerized maintenance managementsystems (CMMS) or can interface with a standalone CMMS. This featuregreatly enhances the automation of and connection between facility opera-tions and equipment maintenance.

Some examples of maintenance control are listed below:

Filter Control. Primary and secondary air handling unit filters can be moni-tored with differential pressure switches, so that when the filter reaches acertain pressure across the media it triggers a maintenance alarm at theDDC operator’s console(s). This alarm can be linked to a message thatgives the maintenance person information on the size and quantity of filtersrequired. This strategy can save staff time as well as reducing energy wastefrom running fans against higher than necessary static pressures.

Water Treatment. Water chemical feed for cooling tower basins and forboiler systems may be administered manually or by a local specialty feeder.An EMS can be programmed to perform this function automatically, adjust-ing the feed rate based on other information to which it has access, such asblow-down or bleed-off rates.

Run-Time Tracking. EMS totalization features can accumulate the total hoursof on-time for any piece of monitored equipment. Alarms can be pro-grammed to notify facility staff when equipment has run for a given num-ber of hours and requires service. Fan motor belts, bearing lubrication,pump seals/packing glands, etc., can be scheduled for maintenance byeither total run-time or calendar dates. The DDC system can trigger mainte-nance alarms and be linked to messages. Run-time can also be used toalternate redundant pumps, chillers, boilers, and other equipment.

Sewer Fee Control. Cooling towers lose water through evaporation andrequire make-up water as well as some periodic blow-down or bleed-off ofwater to keep mineral buildup under control. If utility sewer rates are highand cooling tower flow rates are large enough, it may be cost-effective toinstall water meters on the make-up and blow-down lines. These meterswill calculate the actual amount of water going down the drain to thesewer, allowing for possible reduction of the sewer bill, as the evaporatedwater will not be billed.

Remote EMS Operation

Remote EMS operation usually means remote monitoring or remote con-trol. Some facility managers are responsible for multiple facilities, for ex-ample, a college campus or a network of company retail shops over a largegeographical area. To best manage these situations, facility managers withadvanced communications capabilities can take advantage of local-area net-works or high-speed modems to connect their local computer terminal to aremote building EMS. Depending on the capabilities of the EMS, remoteoperators may be able to perform some control actions such as shuttingdown and starting up equipment.

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NON-ENERGY APPLICATIONS

With increasing technological advances in communications equipment, re-mote monitoring is becoming more widely practiced. Through a telephoneor Internet connection, the offsite computer acts as an EMS terminal andcan access alarms, trend files, and other data. Monitoring a building from aremote location is a good way to view building performance for compari-son with other buildings or to simultaneously manage upgrade projects invarious locations.

ModemModem

RemoteComputer

EMS BoxComputer

LAN Cardin Box

LAN Card inComputer

Building

It may be difficult or impractical to access a remote EMS repeatedly duringthe day. It is best to have trend data saved automatically for download bythe remote user, who can dial in, select the desired trend, and retrieve datafor the past 24 hours (or some other time period). Data storage can oftenbe an issue; to avoid cluttering their systems, many system operators down-load data to a tape drive or some other backup storage area.

Security Applications

Security is of premium importance to most building owners. Some sectors,such as the federal government, are required to maintain certain levels ofsecurity. Other organizations, both public and private, perform sensitivework requiring security clearances and access control. For these reasons,most commercial buildings operate under a form of secured or restrictedaccess. There is often an opportunity for integration of security systemswith EMS and other building systems such as HVAC and lighting. ThroughEMS, today’s advanced security equipment allows facility managers to fur-ther refine security practices to meet their needs more exactly.

Card Key Access

Magnetic card key systems are a standard form of access control. Theirminimum function is that of a lock and key. However, in many buildings,the access cards contain unique digital identification information, allowingfor activity in the building to be remotely monitored and recorded. Fororganizations that wish to conduct in-house security analysis and monitor-ing, particularly during unoccupied hours, card key systems are ideal. Fororganizations that have less need for security monitoring, the access systemvendor will typically store entry data offsite to be retrieved if needed. Al-

FIGURE 7-1.Remote Operation

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CHAPTER 7

though many card key systems can feed data directly to the building EMS,not all have that capability. Work with your security vendor to make sureyour EMS can communicate with your security system.

When access is restricted between zones or floors, card key information isvaluable for analyzing building occupancy trends. When the EMS is inte-grated with the security system, card key readers can act as a form ofoccupancy sensor to augment zone control. This is most successfully andaccurately accomplished with an employee “key-in” and “key-out” system.For example, a worker enters her office space by sliding her access cardthrough the reader, either at the main building entrance or at the entranceon her floor. When this occurs, the reader obtains the employee’s identifi-cation and feeds her data to the EMS. The EMS can then look up the loca-tion of her office space in a database and subsequently activate lighting orzone-level HVAC at that employee’s work space as appropriate. Further-more, lighting and HVAC can be provided only to nighttime or weekendworkers’ zones based on a signal from the card key reader. In this way,access control will produce not only non-energy benefits such as enhancedsecurity monitoring, but energy savings as well.

Industrial Applications

Industrial buildings have HVAC and lighting needs that are very specific tothe nature of the onsite industrial or manufacturing activities. Nevertheless,it may be profitable to take a close look at your onsite processes to seewhether they can be improved by integration with your EMS.

The following are some examples of possible industrial applications:

• Optimizing conveyor belt speed for mass production lines.

• Coordinating and integrating different manufacturing lines.

• Matching shipping with current production levels.

• Interfacing with computerized manufacturing equipment.

• Providing extra cooling upon demand to high-temperature manufactur-ing areas.

• Monitoring production at various points along a manufacturing line.

• Calculating and storing quality-control parameters.

• Providing precise environmental control for “clean rooms.”

• Monitoring raw material inventory levels.

• Handling alarms for industrial applications.

Your process or activity may be currently managed or supervised by acentral computer system, which might be enhanced by integration with theEMS. An EMS is in a unique position to assist industrial applications be-cause of its coverage of the entire building and its central processing power.Work with your controls vendor to develop adaptations.

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NON-ENERGY APPLICATIONS

Retail Applications

Retail stores are in an excellent position to derive non-energy benefits fromenergy management systems. A critical parameter for stores is that of cus-tomer traffic, and the EMS is an excellent vehicle for traffic data collection.With the proper motion sensors, the EMS can measure how many custom-ers are shopping, when they are shopping, and their rates of entry and exit.For larger stores, it is possible to determine the areas of highest trafficwithin the store. A major ancillary benefit of this information is the abilityto measure the effectiveness of promotions and marketing efforts. In thiscase, a direct correlation between the promotion and increases in con-sumer traffic (perhaps in a particular aisle or area), would provide market-ing assessment data.

Additional benefits are possible for multi-store facilities such as malls orshopping centers. Information about customer traffic has traditionally beengathered by counting cars in the parking lots and garages, usually withpneumatic road tubes. Using EMS, you can refine car counting for reliabil-ity, or move toward people-counting instead. When you have the ability todetermine customer traffic at various levels and locations, you will be ableto implement the following tasks:

• Find high- and low-traffic areas.

• Evaluate special events.

• Compare number of shoppers to number of buyers.

• Evaluate business hours.

• Analyze seasonal trends.

• Determine expected shopping activity by day of week.

• Quantify effects of weather on shopping.

• Improve traffic to low-activity areas.

Miscellaneous Applications

Non-energy related tasks are not limited to security, industrial, and retailapplications. Your own creative initiative may come up with successfulapplications for your facility. The following are just of few of the potentialtasks that are presently implemented at facilities across the country.

Greenhouses and Farming. Use EMS to precisely control humidity levels ingreenhouses, to schedule plant watering, or to operate irrigation systems.

Noise Control. Some facilities need to monitor and record noise levels.When possible, use the EMS to ratchet down noise-generating equipmentor to activate noise cancellation systems if decibel levels go above pre-scribed safety levels. In addition, decibel-level logs may help resolve workercomplaints about noise levels.

Environmental Compliance. Many organizations must carefully monitorpollutants or emissions. EMS can handle this job and provide documenta-

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tion. At hazardous waste cleanup sites, EMS can monitor soil for toxic con-taminant levels and generate alarms as required.

Indoor Air-Quality Monitoring. Many building owners with IAQ concernsuse EMS to monitor and troubleshoot carbon dioxide, toxic substances, andhumidity levels.

Animal Farms. EMS has been creatively applied to farming tasks. For ex-ample, at a hog farm, the EMS could schedule and automate feeding timeswhile opening and closing gates to herd animals to the desired locations.

The cost-effectiveness of any application will depend on its benefits. In-creases in productivity and efficiency can be factored into cost analyses;other benefits, such as improved customer relations, full environmentalcompliance, or enhanced security, may be hard to quantify in dollar amountsbut are clearly desirable and worthwhile.

Consider thePossibilities

When considering an expansion

of your EMS into non-energy

tasks, ask yourself if there are any

unusual or atypical needs at your

facility. Are there any regularly

repeated tasks that would benefit

from automation? Is there a need

for information that would be

difficult to collect manually? You

may find unexpected

opportunities.

This appendix contains sample specification language for the followingtopics:

Sample ControlSpecification LanguageSpecific language that is not currently found in many guidespecifications and that may be valuable toward obtaining agood control system.

A P P E N D I X

• Qualification of Manufacturer and Lead InstallingTechnician

• Trend Logging Capabilities

• Extra Monitoring Points, Test Ports, and Gages

• Partial Sample Performance Specification

• Commissioning and Quality Assurance

– Commissioning responsibilities

– Prefunctional testing and initial checkout overview

– Procedures for control systems prefunctional testing and initialcheckout

- Sensor and controller checks- Device calibrations

– System functional testing

– Training of owner personnel

– Operation and maintenance (O&M) manuals

Notes to the reader are enclosed in text boxes to differentiate fromthe actual specification language.

Edit and adapt

this material as

appropriate for

your project.

A-2

APPENDIX A

Qualification of Manufacturer and Lead Installing Technician

Include this language in Division 1 or in the controls Division, as appropriate.

A. Manufacturer and Vendor. Within 14 days after notice to proceed, the controls contractor shall submit to the GC, CM andPM a certified statement, signed by an officer of the manufacturer and vendor which includes the following: name andaddress of company; name, address and telephone number of the local representative; a general sales bulletin coveringthe full line of products manufactured; a certification that the products proposed for this contract have been in continuousand successful use for at least 1 year, not including beta testing, and general information covering the functions andcharacteristics of the systems proposed. In addition, provide a list of four projects which the vendor has installed that aresimilar in size and complexity to this contract, with the name and telephone number of the contracting officer and facilityadministrator, size of project, location and brief description and date of completion.

B. Lead Programmer (LP). The majority of the programming for this project will be completed by the lead programmer.The LP will personally review and approve all programming by others. Within 14 days after notice to proceed, thecontrols contractor shall submit the following regarding the LP: name; address; telephone number; certification of trainingon this system; list of two projects of similar size and complexity to this contract which were primarily programmed bythe LP; and for each project the project name, location, description, cost, name and telephone number of the contractingofficer and current facility administrator and date of completion. A replacement to the LP must be approved in writing bythe Owner.

C. Lead Installation Technician (LIT). The automatic controls will be installed under the direct and continuous supervisionof a lead technician authorized by the manufacturer. Within 14 days after notice to proceed, the controls contractor shallsubmit the following regarding the LIT: name; address; telephone number; certification of training on this system; list oftwo projects of similar size and complexity to this contract which were directly supervised by the LIT; and for eachproject the project name, location, description, cost, name and telephone number of the contracting officer and currentfacility administrator and date of completion. A replacement to the LIT must be approved in writing by the Owner.

D. Acceptance. A review of the qualifications and action upon the acceptance of the manufacturer and the LIT and LP willbe completed by the Owner. If the manufacturer, the proposed product line or the qualifications of the LIT or LP are notin accordance with the Contract Documents or, in the opinion of the Owner, will not result in a satisfactory completedproduct, alternatives must be submitted for approval.

Trend Logging Capabilities

Include this language in the relevant controls section, as appropriate.

A. The control system installed shall be capable of, and set up to readily trend data with the following minimum features.

1. Any point, physical or calculated may be designated for trending. Any point, regardless of physical location in thenetwork, may be collected and stored in each DDC controller’s point group.

2. Collection may be by either predefined time interval or upon a predefined change of value (COV).

3. Each DDC controller panel shall have a dedicated RAM-based buffer for trend data and shall be capable of storing atleast ______________ (e.g., 10,000 to 25,000) samples.

4. At least six columns of data can be viewed on the screen at once and can be graphed using a graphing programintegral to the control system, with at least four parameters graphed against time on the same graph. The columnarformat shall have time down the left column with columns of data to the right (one column for each parameter).

5. The system shall have the ability to graph real-time data of up to four points on the EMS at once, giving each pointits own scale.

6. Without any special or difficult conversions, this data shall be able to be designated to be stored as an ASCII delim-ited file in the same columnar format for use in graphing with normal commercial spreadsheet software.

7. The trend log data is automatically downloaded at appropriate intervals onto the hard drive when space in the fieldcabinets becomes full, so that no data is lost. This is done without the user having to calculate the size of the trendsand download frequency.

A-3

SAMPLE SPECIFICATIONS

8. Any limitations in the trending as to speed of sampling vs number of sampled points in a given trend, and the effecton actual sampling rate and simultaneousness of the sampling across parameters shall be clearly explained in writing.Programming and trending setup examples of all representative situations shall be provided.

9. The trends shall be capable of being set up to start sampling at a future time.10. Specifications for standard trends shall be able to be set up by the user and be saved by a name and initiated by only

recalling the name. The control contractor shall assist the operators in setting up at least six standard trends duringtraining.

11. The system shall have the ability to automatically accumulate and store run-time hours of digital input and outputpoints, to count events (totalization and counting functions).

12. The EMS shall automatically sample, calculate and store consumption totals on a daily, weekly, or monthly basis foruser-selected binary pulse input-type points.

13. The system shall be capable of constructing trends that include averages, minimums, and maximums over anyspecified interval.

14. The capability for the collection time interval to be from 1 minute to 1 day.

15. Ideal, but not required, shall be the capability to graph with the control system software, one or more points againstanother, rather than just against time.

Extra Monitoring Points, Test Ports and Gages

In the controls specification section, under PART 2 - PRODUCTS, provide requirements for including additionalcontrol points and test ports and gages for commissioning and better operation of the system over time. Use thelanguage below, as appropriate.The A/E and the design phase CA should review this list and determine which points should be included in thisproject (including any not listed). TAB and commissioning costs will be lower when appropriate additional pointsare included, and the troubleshooting process for the building operators will be improved. It is not assumed that allthose points listed are needed. The value of any given point is dependent on the equipment and system, theexpertise of the operating staff to make use of the points, the size of the equipment, etc.

MONITORED POINTS

A. All control points of the central building automation system, required to automatically control the equipment specified inthe Contract Documents and to execute all specified control sequences, shall be installed and be able to be monitored. Tosimplify TAB and commissioning of the systems and to provide better control during occupancy, the following points shallbe provided as monitored points in the control system, even if they are part of equipment integral controls, or are notrequired in any control sequence or intermediate calculation. Some points may be measured values or output signals,while others may be calculated or virtual points. Many points listed below may already be required to control theequipment.

[LIST DESIRED POINTS]

TEST PORTS

A. The controls contractor shall provide test ports for handheld instrument readings near all piping system sensors in theprimary system (not at the zone level).

GAGES

A. The controls contractor shall provide gages in the following locations, even if included as a sensor and monitored point inthe control system:

1. Pressure gages on both sides of all pumps greater than 1 hp.

2. Mercury thermometers in the return and supply of all primary thermal plant equipment (chillers, cooling towers,boilers, converters, etc.).

A-4

APPENDIX A

Partial Sample Performance Specification

This section provides the facility manager with an example of what performance specification language is like. It isnot comprehensive and the values used for performance criteria may not be appropriate for your facility. Consultwith a controls or systems designer to develop performance specifications for your project.

A. Provide a complete control system, consisting primarily of electronic direct digital control devices. Arrange each loop tohave PID (proportional, integral, derivative) control capability, but initially arrange for PI control.

B. The building automation and DDC control system shall possess a fully modular architecture, permitting expansion throughthe addition of standalone control units, modular building controllers, unitary controllers, digital point units, multiplepoint units, terminal equipment controllers, operator terminals, personal computers, and/or a general purpose multi-tasking, multi-operator minicomputer.

C. Provide all equipment, installation, and accessories as required, but not necessarily specified, to accomplish the opera-tions as a fully functional system as described.

D. Arrange DDC system to control space temperature within a range of 50ºF to 85ºF + 1.0ºF for conditioned space (display tonearest 0.5ºF). Unless otherwise specified, change of value reporting shall not be required to be less than 0.5ºF.

E. Arrange DDC system to control duct temperature within a range of 30ºF to 130ºF. + 1.0ºF (display to nearest 0.5ºF). Unlessotherwise specified, change of value reporting shall not be required to be less than 1.0ºF.

F. Arrange DDC system to control water temperature within a range of 40ºF to 280ºF. + 1.0ºF (display to nearest 0.5ºF).Unless otherwise specified, change of value reporting shall not be required to be less than 1.0ºF.

G. Arrange DDC system to control duct static and building static pressure with a range for the specific application + 25percent of range. Display shall be to within + 0.01" W.C. Unless otherwise specified, change of value shall not be requiredto be less than 0.05" W.C.

H. Arrange DDC system to control space humidity within a range of 10 to 90 percent R.H. + 3.0 percent R.H for conditionedspace (display to nearest 1.0 percent R.H.). Unless otherwise specified, change of value reporting shall not be required tobe less than 1.0 percent R.H. Unless otherwise specified, response time shall be no greater than 45 seconds.

I. Arrange DDC system to control duct humidity within a range of 0 to 100 percent R.H. + 5.0 percent R.H. (display tonearest 1.0 percent R.H.). Unless otherwise specified, change of value reporting shall not be required to be less than 1.0percent R.H. Unless otherwise specified, response time shall be no greater than 45 seconds.

J. Arrange DDC signals to precisely sequence heating valves, dampers, and cooling valves without overlaps. Unless other-wise specified, sequenced devices will have a separate DDC output for each device. Spring range sequencing will not bepermitted.

K. Each start/stop function shall be controlled from a separate DDC output.

L. Contractor to functionally test each existing valve, damper operator, freeze protection thermostat, and all other existingdevices that will operate in conjunction with the DDC system and notify the (owner, or owner’s representative) projectmanager/coordinator of any work that is inoperative, or malfunctioning devices found. The Owner may direct theContractor to repair or replace such devices under a supplemental contract.

M. All materials, parts, components, installed equipment, products, etc., supplied as part of this product shall be new andunused.

A-5


Commissioning and Quality Assurance

This section contains language that covers the primary commissioning requirements for a controls system installa-tion. Complete commissioning details for all parts of the commissioning process for all parties can be found in thesources listed at the end of Chapter 3: Commissioning New Energy Management Systems. Include the language inthe following section in specification Division 1 or another appropriate Division.

Quality Assurance. Quality assurance for automatic controls systems shall be accomplished through the commissioningprocess consisting of submittal review of system engineering work, documented prefunctional testing and initial checkout,documented functional performance testing, operator training and O&M documentation. In addition there will be aqualification procedure for the manufacturer and lead installation technician.

Related Sections. The general commissioning process procedures and requirements are given in Section 17100 withresponsibilities unique to Division 15 included in Section 15995, including O&M manual documentation and trainingrequirements. The common process requirements for initial system checkout are found in Section 17100. Specific func-tional testing requirements are identified in Section 15997. Specific prefunctional checklists are found in Section 15998 andsample functional test procedure formats are found in Section 15999.

Include the following language in Division 15 or an appropriate quality assurance or commissioning division.This language covers the controls contractor responsibilities.

1.1 COMMISSIONING RESPONSIBILITIES

A. Mechanical, Controls and TAB Contractors. The commissioning responsibilities applicable to each of the mechanical,controls and TAB contractors that may be involved in this project are:

1. Include the cost of commissioning in the contract price.

2. In each purchase order or subcontract written, include requirements for submittal data, O&M data and training.

3. Attend any commissioning scoping meeting and other necessary meetings scheduled by the commissioning agent(CA) to facilitate the Cx process.

4. Provide limited assistance to the CA in preparation of the specific functional performance test procedures. Contrac-tors shall review test procedures to ensure feasibility, safety and equipment protection and provide necessary writtenalarm limits to be used during the tests.

5. Develop a full startup and initial checkout plan using manufacturer’s startup procedures and the prefunctionalchecklists from the CA. Contractors submit manufacturer’s detailed startup procedures and the full startup plan andprocedures and other requested equipment documentation to CA for review.

6. During the startup and initial checkout process, execute prefunctional procedures provided by the CA.

7. Perform and clearly document all startup and system operational checkout procedures, providing a copy to the CA,including factory startups.

8. Address current A/E or Owner punch list items before functional testing. Air and water TAB shall be completed withdiscrepancies and problems remedied before functional testing of the respective air- or water-related systems.

9. Provide skilled technicians to execute starting of equipment and to execute the functional performance tests. Ensurethat they are available and present during the agreed upon schedules and for sufficient duration to complete thenecessary tests, adjustments and problem-solving.

10. Perform functional performance testing under the direction of the CA. Assist the CA in interpreting the monitoringdata, as necessary.

11. Correct deficiencies (differences between specified and observed performance) as interpreted by the CA, Owner andA/E and retest the equipment.

12. Prepare O&M manuals according to the Contract Documents, including clarifying and updating the original se-quences of operation to as-built conditions.

13. Prepare red-line as-built drawings.

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APPENDIX A

14. Provide training of the Owner’s operating personnel as specified.

15. Coordinate with equipment manufacturers to determine specific requirements to maintain the validity of the warranty.

B. Controls Contractor. The commissioning responsibilities of the controls contractor, in addition to those listed in (A) are:

1. If the Owner engages a TAB contractor, assist and cooperate with the TAB contractor in the following manner:

a) Meet with the TAB contractor prior to beginning TAB and review the TAB plan to determine the capabilities ofthe control system toward completing TAB. Provide the TAB any needed unique instruments, software andinterface cables for setting terminal unit boxes and instruct TAB their use (handheld control system interface foruse around the building during TAB, etc.).

b) Have all CA-required prefunctional checklists, calibrations, startup and selected functional tests of the systemcompleted and approved by the CA prior to TAB.

c) Provide a qualified technician to operate the controls to assist the TAB contractor in performing TAB.

2. Assist and cooperate with the CA in the following manner:

a) Execute the functional testing of the controls system and other equipment as specified.

b) Execute all control system trend logs requested by the CA to demonstrate proper system function.

3. The controls contractor shall prepare and submit to the CA a written plan indicating in a step-by-step manner, theprocedures that will be followed to test, checkout and adjust the control system prior to functional performancetesting. At minimum, the plan shall include for each system and subsystem controlled by the automatic controls:

a) System name

b) List of devices with a brief description of functional purpose of each.

c) Step-by-step procedures for testing each controller after installation.

d) Indicate what tests on what systems should be completed prior to TAB using the control system for TAB work.Coordinate with the TAB contractor for this determination.

4. Provide a signed and dated certification to the CA or Owner upon completion of the checkout, prior to functionaltesting, that all system programming is complete as to all respects of the Contract Documents, excepting functionaltesting requirements.

5. List and clearly identify on the as-built drawings the locations of all static and differential pressure sensors (air, waterand building pressure).

6. Sample and minimum initial checkout procedures are provided in Section 3.8.

C. The commissioning agent will be hired by the Owner.

1.2 PREFUNCTIONAL TESTING AND INITIAL CHECKOUT OVERVIEW

A. The control contractor will be responsible to perform their initial checkout of the system. This will ensure that all compo-nents are installed, calibrated and operating. Section 1.3 provides minimum requirements for the initial checkout. The CAdoes not oversee the checkout, but approves the plan and submitted documentation and may witness parts of theprocess.

B. The contractor will complete the initial checkout and submit the documentation verifying the completion of the work tothe CA.

C. Deficiencies and Nonconformance in Checklists and Startup.

1. The Contractor shall clearly list any outstanding items of the initial startup and prefunctional procedures that werenot completed successfully, at the bottom of the procedures form or on an attached sheet. The procedures form anddeficiencies are provided to the CA within two days of test completion.

2. The CA shall work with the Contractor and vendors to correct and retest deficiencies or uncompleted items. The CAwill involve the Owner and others as necessary. The installing Contractors or vendors shall correct all areas that aredeficient or incomplete in the checklists and tests in a timely manner, and shall notify the CA as soon as outstandingitems have been corrected and resubmit an updated startup report. The CA recommends approval of the execution ofthe checklists and startup of each system to the Owner using a standard form.

3. Items left incomplete, which later cause deficiencies or delays during functional testing may result in backcharges tothe responsible Contractor.

A-7


1.3 PROCEDURES FOR CONTROL SYSTEMS PREFUNCTIONAL TESTING AND INITIAL CHECKOUT

The controls contractor shall incorporate the following procedures with the manufacturer’s recommended checkoutprocedures into a testing and checkout plan, in a “checklist” format according the requirements in this Section.

A. Prefunctional Checklists, Tests and Initial Checkout Procedures

1. Requirements. The following requirements are minimums. The controls contractor is encouraged to identify betterand more comprehensive checkout procedures in their submitted plan. These procedures are not a substitute for themanufacturer’s recommended startup and checkout procedures, but are to be combined with them.

2. General Installation. The following are required checklist items.

a) Layout of control panel matches drawings.

b) Framed instructions mounted in or near panel.

c) Components properly labeled (on inside outside of panel).

d) Control components piped and/or wired to labeled terminal strip(s).

e) EMS connection made to labeled terminal(s) as shown on drawings.

f) Control wiring and tubing labeled at all splices, junctions and terminations.

g) Shielded wiring used on electronic sensors.

h) 110 volt AC power available to panel.

i) Psig compressed air available to panel.

j) Battery backup in place.

k) Panels properly grounded

l) Environmental conditions according to manufacturer’s requirements

m) Date and time correct.

n) All valves checked for installation in the proper direction.

o) Proper application of normally open or normally closed valves.

p) All sensor locations appropriate and away from causes of erratic operation.

3. Sensor And Controller Checks. A complete point-to-point check will be completed and documented by the controlscontractor on forms approved previously by the CA. All sensors, actuators, controller and control points will bechecked and calibrated. The minimum rigor in calibrating controllers and sensors shall be as follows: (These proce-dures are not a replacement for the manufacturer’s recommended installation, setup and checkout procedures.)

4. Sensor Calibrations.

a) All Sensors. Verify that all sensor locations are appropriate and away from causes of erratic operation. For sensorpairs that are used to determine a temperature or pressure difference, make sure they are reading within 0.2ºF ofeach other for temperature and within a tolerance equal to 2% of the reading, of each other, for pressure.Tolerances for critical applications may be tighter.

b) Stats. Slowly adjust the setpoint of the thermostat or humidistat until the current conditions cause the contacts tobe made or broken. At that point, record the reading of the stat. Immediately record and compare the reading ofa calibrated testing instrument held within six inches of the stat. The accepted tolerances for calibrating statsusing this method are double those found in the table below.

c) Sensors without Transmitters. Standard Application. Make a reading with a calibrated test instrument within 6inches of the site sensor. Verify that the sensor reading (via the permanent thermostat, gage or building automa-tion system (BAS)) is within the tolerances in the table below of the instrument-measured value. If not, installoffset in BAS, calibrate or replace sensor.

d) Sensors with Transmitters. Standard Application. Disconnect sensor. Connect a signal generator in place ofsensor. Connect ammeter in series between transmitter and BAS control panel. Using manufacturer’s resistance-temperature data, simulate minimum desired temperature. Adjust transmitter potentiometer zero until 4 mA isread by the ammeter. Repeat for the maximum temperature matching 20 mA to the potentiometer span ormaximum and verify at the BAS. Record all values and recalibrate controller as necessary to conform withspecified control ramps, reset schedules, proportional relationship, reset relationship and P/I reaction. Reconnect

A-8

APPENDIX A

sensor. Make a reading with a calibrated test instrument within 6 inches of the site sensor. Verify that the sensorreading (via the permanent thermostat, gage or building automation system (BAS) is within the tolerances in thetable below of the instrument-measured value. If not, replace sensor and repeat. For pressure sensors, perform asimilar process with a suitable signal generator.

Table A-1. Tolerances for Standard Applications

Sensor Required Sensor RequiredTolerance (+/-) Tolerance (+/-)

Cooling coil, chilled andcondenser water temperatures 0.5ºF Flow rates, water 4% of design

AHU wet bulb or dew point 1.0ºF Combustion flue 5.0ºFtemperatures

Hot water coil and boiler 2.0ºF Oxygen or CO2 monitor 0.1% pts

water temperature

Outside air, space air, coil air 0.5ºF CO monitor 0.01% ptstemperatures

Watt-hour, voltage, and amperage 1% of design Natural gas and oil flow 1% of design

Pressures: air, water, and gas 3% of design Steam flow rate 3% of design

Flow rates: air 10% of design Barometric pressure 0.1 inches Hg

e) Critical Applications. For critical applications (process, manufacturing, etc.) more rigorous calibration techniquesmay be required for selected sensors. Describe any such methods used on an attached sheet.

5. Device Calibrations.

For all controlled devices, verify by visual inspection that the position displayed in the energy management system isthe actual position in the field. Also, verify for all valves 3 inches or greater and for 75% of 2 inch valves and 10% of1 inch valves that there is no leakage when closed, using the methods below or other suitable method.

a) Valve Spanning. For all valve and actuator positions checked, verify the actual position against the EMS readout.Set pumps to normal operating mode. Command valve closed, verify that valve is closed and adjust output zerosignal as required. Command valve open, verify position is full open and adjust output signal as required.Command valve to a few intermediate positions. If actual valve position doesn’t reasonably correspond, replaceactuator or add pilot positioner (for pneumatics).

b) Heating Coil Valves (Normally Open). Set heating setpoint 20ºF above room temperature. Observe valve open.Remove control air or power from the valve and verify that the valve stem and actuator position do not change.Restore to normal. Set heating setpoint to 20ºF below room temperature. Observe the valve close. For pneumat-ics, by override in the EMS, increase pressure to valve by 3 psi (do not exceed actuator pressure rating) andverify valve stem and actuator position does not change. Restore to normal.

c) Cooling Coil Valves (Normally Closed). Set cooling setpoint 20ºF above room temperature. Observe the valveclose. Remove control air or power from the valve and verify that the valve stem and actuator position do notchange. Restore to normal. Set cooling setpoint to 20ºF below room temperature. Observe valve open. Forpneumatics, by override in the EMS, increase pressure to valve by 3 psi (do not exceed actuator pressure rating)and verify valve stem and actuator position does not change. Restore to normal.

A-9


d) Valve Leak Check

i. Method 1: Water Temperature with 2-Way Valve. This test is for pipe with 1 inch of fiberglass insulation.Calibrate sensors used for both sides of valves to within 0.5F. If there is a coil involved, turn off air handlerfans and close the OSA dampers. Close valve with EMS. Insert a probe downstream of valve. Insert probeupstream in moving flow or use EMS value. (If no P/T plug downstream, put firmly on pipe wall underinsulation and assume about a 2ºF rise in water temperature.) Take initial readings and record. With pumpon, wait 1 hour for 1 inch pipe, 2 hours for 2 inch, 3 hours for 3 inch and 4 hours for 4 inch diameter pipe.If after the waiting period, the water temperature downstream hasn’t changed by at least the values shownin the table (for the appropriate dT), there is likely leak-by. If leak-by is suspected, increase closingpressure or re-span actuator to get a tighter close-off and repeat test.

Table A-2. Minimum Expected Water Temperature Change When No Leak

Initial dT (ambient air – water)

30 50 70 90

1 inch pipe after 1 hour 9 14 20 26

2 inch pipe after 2 hours 7 12 16 21



i. Method 2: Valves Near Coils: Air Temperature with 2- or 3-Way Valve. Calibrate air temperature sensors oneach side of coil to be within 0.5ºF of each other. Change mixed or discharge air setpoint, override valuesor bleed or squeeze bulb pneumatic controller to cause the valve to close. Air handler fans should be onand pump flow through coil fairly constant. After 5 minutes, observe air delta T across coil. If it is greaterthan 1ºF, leakage is probably occurring. Reset valve stroke to close tighter. Repeat test until compliance.

ii. Method 3: Drain Down (for Small Coils). With the water system in normal (pump running) and the zonecalling for full coil demand, close coil supply isolation valve, open air bleed cap, open drain-down cockand drain water from coil. Water should stop draining from coil, else there is likely leakage through thecoil. Return all to normal when complete. This method is not applicable to 3-way valves.

e) Damper Spanning. Set air handlers to normal operating mode. Command or simulate conditions so dampercloses. Verify that the damper is closed and adjust output zero signal as required. Command damper open, verifyposition is full open and adjust output signal as required. Command dampers to a few intermediate positions. Ifactual damper position doesn’t reasonably correspond, replace actuator or add pilot positioner (for pneumatics).

1.4. SYSTEM FUNCTIONAL TESTING

The “Model Commissioning Plan and Guide Specifications” referenced at the end of Chapter 3 contains sample testrequirements and procedures for many types of typical equipment.

A. The controls system will be functionally tested after the controls contractor has completed the initial checkout. Thecommissioning authority (CA) with the Owner will then perform tests of the functionality of the controls and the systemswhich they control. The functional tests procedures and forms will be developed by the CA and reviewed by the controlscontractor.

B. Test Scope. The tests will primarily consist of taking each piece of equipment controlled in any way by the EMS andrunning it through its sequences of operation, including startup, shutdown, unoccupied mode and power failure, capacitymodulation, interlocks, etc. and verifying that they operate according to the sequences and the intended operation. Theprocess will be documented by the CA on forms for that purpose. Additionally, the controls contractor will be responsibleto provide trend logs in spreadsheet columnar format, as requested by the CA, for verification of many of the sequencesof operation.

(1-inch fiberglass insulation assumed)

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APPENDIX A

C. The controls contractor is responsible to operate the controls system during the tests.

D. Nonconformance.

1. The CA will record the results of the functional test on the procedure or test form. All deficiencies or nonconfor-mance issues shall be noted and reported to the Owner on a standard form.

2. Corrections of minor deficiencies identified may be made during the tests at the discretion of the CA. In such casesthe deficiency and resolution will be documented.

3. Every effort will be made to expedite the testing process and minimize unnecessary delays, while not compromisingthe integrity of the procedures. That is, the CA will not be pressured into accepting work that is deficient, to satisfyscheduling or cost issues, unless there is an overriding reason to do so and the permission of the Owner has beenobtained.

4. As tests progress and a deficiency is identified, the CA discusses the issue with the executing contractor.

a) When there is no dispute on the deficiency and the Contractor accepts responsibility to correct it:

i. The CA documents the deficiency and the Contractor’s response and intentions and they skip to anothertest or sequence. After the day’s work, the CA submits the noncompliance report to the Owner, if required,who signs and provides a copy to the Contractor. The Contractor corrects the deficiency, signs the state-ment of correction at the bottom of the noncompliance form certifying that the equipment is ready to beretested and sends it back to the CA.

ii. The CA reschedules the test and the test is repeated.

b) If there is a dispute about a deficiency, regarding whether it is a deficiency or who is responsible:

i. The deficiency shall be documented on the noncompliance form with the Contractor’s response and a copygiven to the Owner and to the Contractor representative assumed to be responsible.

ii. Resolutions are made at the lowest level possible. Other parties are brought into the discussions as needed.Final interpretive authority is with the A/E. Final acceptance authority is with the Project Manager.

iii. The CA documents the resolution process.iv. Once the interpretation and resolution have been decided, the appropriate party corrects the deficiency,

signs the statement of correction on the noncompliance form and provides it to the CA. The CA resched-ules the test and the test is repeated until satisfactory performance is achieved.

5. Cost of Retesting.

a) The cost for the Contractor to retest a prefunctional or functional test, if they are responsible for the deficiency,shall be theirs. If they are not responsible, any cost recovery for retesting costs shall be negotiated with theprime contractor.

b) For a deficiency identified, not related to any prefunctional checklist or startup fault, the following shall apply:The CA and Owner will direct the retesting of the equipment once at no “charge” for their time. However, theCA’s and Owner’s time for a second retest will be backcharged to the Contractor.

c) The time for the CA and Owner to direct any retesting required because a specific prefunctional checklist orstartup test item, reported to have been successfully completed, but determined during functional testing to befaulty, will be backcharged to the Contractor.

6. The Contractor shall respond in writing to the CA and Owner at least monthly concerning the status of each apparentoutstanding discrepancy identified during commissioning. Discussion shall cover explanations of any disagreementsand proposals for their resolution.

7. The CA retains the original nonconformance forms until the end of the project.

E. Failure Due to Manufacturer Defect. If 10%, or three, whichever is greater, of identical pieces (size alone does notconstitute a difference) of equipment fail to perform to the Contract Documents (mechanically or substantively) due tomanufacturing defect, not allowing it to meet its submitted performance spec, all identical units may be consideredunnacceptable by the Owner. In such case, the Contractor shall provide the Owner with the following:

1. Within two weeks of notification from the Owner, the Contractor or manufacturer’ representative shall examine allother identical units making a record of the findings. The findings shall be provided to the Owner within four weeksof the original notice.

2. Within six weeks of the original notification, the Contractor or manufacturer shall provide a signed and dated, written

A-11


explanation of the problem, cause of failures, etc. and all proposed solutions which shall include full equipmentsubmittals. The proposed solutions shall not significantly exceed the specification requirements of the originalinstallation.

3. The Owner will determine whether a replacement of all identical units or a repair is acceptable.

4. Two examples of the proposed solution will be installed by the Contractor and the Owner will be allowed to test theinstallations for up to two weeks, upon which the Owner will decide whether to accept the solution.

5. Upon acceptance, the Contractor and/or manufacturer shall replace or repair all identical items, at their expense andextend the warranty accordingly, if the original equipment warranty had begun. The replacement/repair work shallproceed with reasonable speed beginning within two weeks from when parts can be obtained.

F. Approval. The CA notes each satisfactorily demonstrated function on the test form. Formal approval of the functional testis made later after review by the CA and by the Owner, if necessary. The CA recommends acceptance of each test to theOwner using a standard form. The Owner gives final approval on each test using the same form. The CA providesapproval forms to the Contractors upon signing by the Owner.

1.5. TRAINING OF OWNER PERSONNEL

A. The commissioning agent (CA) shall coordinate the training of Owner personnel for commissioned equipment or systems.

B. Controls Contractor. The controls contractor shall have the following training responsibilities:

1. Provide the CA with a training plan two weeks before the planned training.

2. The controls contractor shall provide designated Owner personnel (up to three) training on the control system in thisfacility. The intent is to clearly and completely instruct the Owner on all the capabilities of the control system.

3. Training manuals. Training manuals will be provided for each trainee with two extra copies left for the O&M manu-als. Manuals shall include detailed description of the subject matter for each session. The manuals will cover allcontrol sequences and have a definitions section that fully describes all words used in the manuals and in allsoftware displays. Manuals will be approved by the CA. Copies of audiovisuals shall be delivered to the Owner.

4. The trainings will be tailored to the needs and skill-level of the trainees.

5. The trainers will be knowledgeable on the system and its use in buildings. For the onsite sessions, the most qualifiedtrainer(s) will be used.

6. During any demonstration, should the system fail to perform in accordance with the requirements of the O&Mmanual or sequence of operations, the system will be repaired or adjusted as necessary and the demonstrationrepeated.

7. There shall be three training sessions:

a) Training I. The first training shall consist of 8 hours of actual training. This training may be held onsite or in thesupplier’s facility. If held offsite, the training may occur prior to final completion of the system installation. Uponcompletion, each student, using appropriate documentation, should be able to perform elementary operationsand describe general hardware architecture and functionality of the system.

b) Training II. The second session shall be held onsite for a period of 32 hours of actual training after the comple-tion of system commissioning. The session shall include instruction on:

i. Specific hardware configuration of installed system and specific instruction for operating the installedsystem, including HVAC systems, lighting controls and any interface with security and communicationsystems.

ii. Security levels, alarms, system startup, shutdown, power outage and restart routines, changing setpointsand other typical changed parameters, overrides, freeze protection, manual operation of equipment,optional control strategies that can be considered, energy savings strategies and setpoints that if changedwill adversely affect energy consumption, energy accounting, procedures for obtaining vendor assistance,etc.

iii. All trending and monitoring features, including setting up, executing, downloading, viewing both tabularand graphically and printing trends. Trainees will actually set up trends in the presence of the trainer.

iv. Every screen shall be completely discussed, allowing time for questions.v. Use of keypad or plug-in laptop computer at the zone level.

A-12

APPENDIX A

vi. Use of remote access to the system via phone lines or networks.vii. Graphics generationviii. Point database entry and modificationsix. Understanding DDC field panel operating programming (when applicable)

c) Training III. The third training will be conducted onsite six months after occupancy and consist of 16 hours oftraining. The session will be structured to address specific topics that trainees need to discuss and to answerquestions concerning operation of the system.

1.6. OPERATION AND MAINTENANCE (O&M) MANUALS

The following O&M documentation requirements assume that the general contractor is compiling the O&M manu-als, with all Subs compiling their own sections, including some submissions for the A/E and CA.These requirements may need to be merged and edited to follow the protocols and scope of the current agency orproject. However, the comprehensiveness and accessibility described herein shall be maintained.

A. The following O&M manual requirements do not replace O&M manual documentation requirements elsewhere in thesespecifications.

B. Division 15 shall compile and prepare documentation for all equipment and systems covered in Division 15 and deliverthis documentation to the GC for inclusion in the O&M manuals, according to this section and Section 01730, prior to thetraining of owner personnel.

C. The CA shall receive a copy of the O&M manuals for review.

D. Special Control System O&M Manual Requirements. In addition to documentation that may be specified elsewhere,the controls contractor shall compile and organize at minimum the following data on the control system in labeled 3-ringbinders with indexed tabs.

1. Three copies of the controls training manuals in a separate manual from the O&M manuals.

2. Operation and Maintenance Manuals containing:

a) Specific instructions on how to perform and apply all functions, features, modes, etc. mentioned in the controlstraining sections of this specification and other features of this system. These instructions shall be step-by-step.Indexes and clear tables of contents shall be included. The detailed technical manual for programming andcustomizing control loops and algorithms shall be included.

b) Full as-built set of control drawings (refer to Submittal section above for details).

c) Full as-built sequence of operations for each piece of equipment.

d) Full points list. In addition to the updated points list required in the original submittals (Part 1 of this section), alisting of all rooms shall be provided with the following information for each room:

i. Floorii. Room numberiii. Room nameiv. Air handler unit IDv. Reference drawing numbervi. Air terminal unit tag IDvii. Heating and/or cooling valve tag IDviii. Minimum cfmix. Maximum cfm

e) Full print out of all schedules and setpoints after testing and acceptance of the system.

f) Full as-built print out of software program.

g) Electronic copy on disk of the entire program for this facility.

h) Marking of all system sensors and thermostats on the as-built floor plan and mechanical drawings with their

A-13


control system designations.

i) Maintenance instructions, including sensor calibration requirements and methods by sensor type, etc.

j) Control equipment component submittals, parts lists, etc.

k) Warranty requirements.

l) Copies of all checkout tests and calibrations performed by the Contractor (not commissioning tests).

3. The manual shall be organized and subdivided with permanently labeled tabs for each of the following data in thegiven order:

a) Sequences of operation

b) Control drawings

c) Points lists

d) Controller / module data

e) Thermostats and timers

f) Sensors and dP switches

g) Valves and valve actuators

h) Dampers and damper actuators

i) Program setups (software program printouts)

4. Field checkout sheets and trend logs should be provided to the CA for inclusion in the Commissioning Record Book.

E. Review and Approvals. Review of the commissioning related sections of the O&M manuals shall be made by the A/Eand by the CA.

A-14

APPENDIX A

Using Spreadsheets forGraphing and AnalyzingTrend DataFundamental tips on converting EMS data to graphs usingspreadsheets. (Refer to the Trending section of Chapter 6 fordetails about setting up trend logs.)

A P P E N D I X

Converting to Spreadsheet Format

EMS data must usually be converted to another file format before use ina spreadsheet. In some systems, conversion to spreadsheet format isdone after the data have been gathered; others allow the operator tochoose the appropriate format beforehand. Storing data in a text file(.txt) with commas or tab separators between columns works well, butrequires a conversion when importing to a spreadsheet. The preferredformat is .csv, which requires no conversion by the spreadsheet. Makesure the layout of the stored data has date and time down the left columnand as many columns of parameter values to the right as possible. SeeFigure 5-1, in Chapter 5: Strategies for Optimization, for an example.Don’t allow data in large trends to start a set of new parameters at theend of the columns of the preceding data set. Read the EMS manual andcall the vendor for help, as necessary. Before starting an important trend,experiment on a small trend to be sure the conversion process works.

Opening Data Files

When opening a data file, if it is not a spreadsheet or a .csv file, you willhave to parse or delimit (divide) the data into columns. Newer spread-sheet software will automatically provide a systematic process to do this.Simply observe the data on the screen and mark where you want eachcolumn division. Scroll down into the columnar data past the text infor-mation at the top of the sheet. Put one column marker between eachdata point column. If the data spans more than two days, it is oftenuseful to keep the day and the time together in one column. The spread-sheet can read them together. For trends of two days or less, separate theday from the hour/minute columns (later, graph only the hour and minutecolumn). After parsing but before graphing, save the file as a spread-sheet file type, not as a .txt file.

Using spreadsheets is the

most versatile method of

analyzing trend data

B-2

APPENDIX B

Setting Up GraphsUse the following pointers when setting up graphs:

Combine data files if necessary. Often the points to be graphed togetherare found in different downloaded files. Open both files and combine thedesired columns of data into one file before graphing. If data from one filehas different time intervals, copy in the time column with the data.

Remove extraneous text. Some EMS data files will come with a few rowsof text every 66 lines or so (for a page break). Delete non-data rows beforegraphing. (Macros can be used to do this.)

Convert text data entries to values. Status or COV trends, with “on or off”or “open or closed” as the column values, require some editing before theycan be graphed. Perform a search and replace with “on” replaced by a “1” orsome other value in scale with other variables being graphed and “off” re-placed by “0” or other suitable value. Text such as “alarm,” “missing data,” or“-99” (missing) may need conversion as well.

Arrange columns as needed. Often you may not want to select all thecolumns of data in a spreadsheet for a single graph. Typically, having morethan four data points on a graph makes interpretation difficult. To selectcolumns that are not adjacent to each other, try pressing control or otherfunction keys to allow selecting non-adjacent columns. Otherwise you willhave to move the columns of data manually to be adjacent to each other.

Graphing. The easiest way to graph in newer spreadsheets is to use thegraphing wizard step-by-step procedure. Refer to your spreadsheet manualfor details. Most graphing wizards choose the left-most column as the X-axisdata. If the date and the time are in different columns, select only the daycolumn for graphing.

Once a graph is developed, additional points (columns) can be added ordeleted.

Types of GraphsFor time-series graphs (where time is the X-axis), it is best to designate thegraph as an “XY plot” or a “line graph.” For plotting one parameter againstanother, use “scatter plot” graphs without lines.

ScalingSetting up the proper Y-axis scale is critical for obtaining good resolution.The spreadsheet may default to zero as the minimum and some value abovethe maximum data point for the maximum. This often makes interpretationof the data difficult. In newer spreadsheets, you can change the scale byclicking on the Y-axis and going to the appropriate menu. Normally, youwant the maximum and minimum values to be set so the plot approachesthe top and bottom of the graph at some point.

The X-axis may also need to be scaled or truncated to provide a “zoomed in”view of the data, if more resolution will help the analysis. Start the graphwhen something of interest is happening and end it when the area of inter-est is past by clicking on the X-axis and scaling as necessary.

B-3

SPREADSHEETS

Multiple Y-AxesWhen graphing two or more variableswith a wide range of values, scalingthe left Y-axis may not provide suffi-cient resolution. In such cases, assignthe variables with similar maximumand minimum values to the right orsecond Y-axis. This greatly enhancesthe resolution of the data while stillproviding the comparison of all datato the common X-axis (time). FigureB-1 illustrates this. In the top graph,the spreadsheet default, there is littleresolution to analyze the real relation-ship between the space temperatureand the heating coil valve. In the lowergraph, the coil valve data was assignedto the right Y-axis and scaled; the in-terpretation is clear. The dual-axis for-matting illuminates a problem indicatedby the data: Most of the time, the heat-ing valve does not open more than10%, although the zone temperatureis continually below the setpointdeadband of 71ºF.

Formatting

If the graphs are to be printed for pre-sentation or review by others, theymust be clearly legible. Increasing fontsizes and adding notes to the graph is easily done. Make sure to note onthe graph: the file name; the date of the trend; the equipment and datapoints being shown; the units of each data point; and the sampling inter-val. Experiment with having a data series as a line, symbols only, or both,to improve clarity. In some spreadsheets, output may vary depending onwhether you select the spreadsheet area behind the graph and print, orselect the graph (or chart) itself and print. The key to formatting is toexperiment until you are familiar with your options.

Graphing One Parameter Against Another

In spreadsheets, one parameter can be graphed against another. This isvery useful for many types of diagnostics. For this type of graph, use onlya scatter plot. One column of data (rather than time) gives the X-axisvalues and another column gives the Y-axis data. You can add lines later,if the X data were previously sorted in ascending or descending order andthere are no missing X data.

FIGURE B-1.Effect of Using a Secondary Y-Axis

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Zone Temperature

Zone Temperature, F

Hot Water Coil Valve,Percent Open

Hot Water Coil Valve,Percent Open

Terminal Unit Trend Data--Single Axis

Terminal Unit Trend Data--Dual Axis

HW

Val

ve, %

Ope

n

B-4

APPENDIX B

Figures B-2 and B-3 illustrate the concept. Figure B-2 is a typical time-seriesgraph with the heating water supply temperature (HWST) and the outside airtemperature (OSAT) plotted against time. This particular EMS was supposed tohave a HWST setpoint reset schedule of OSAT 20ºF, HWST 180ºF; OSAT 70ºF,HWST 120ºF. It can be seen from Figure B-2 that the HWST does drop as theOSAT increases, but it is difficult to ascertain accurately whether it follows thespecified schedule. OSAT could be assigned to the right Y-axis for more reso-lution. A very convincing approach is to simply plot the HWST against theOSAT, as in Figure B-3. Scale the graph so the end points of the graph are thesame as the end points of the schedule and draw in the schedule line. It can beclearly seen that the reset schedule is not working as intended, as all points are12 to 15ºF higher than the design schedule.

Trends with Different Time-Steps

In some spreadsheets, separate time-series trends with different time intervals(e.g., 2-minute and 15-minute) can be plotted on the same graph. To do this,bring the data with its associated time stamps into a common spreadsheet.Graph one pair of data. Do not use a scatter plot. Then go to the chart or graphdata-source options and add the new X-axis values (time) and its associated Y-axis values. The data for both Y-series will be plotted on a common X-axis.

FIGURE B-2.Investigation of Reset Schedule via Time-Series Plot

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01:12 2:24 3:36 4:48 6:00 7:12 8:24 9:36 10:48 12:00 13:12

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FIGURE B-3.Investigation of Reset Schedule via Plotting One Parameter Against Another

List of Acronyms,

Bibliography,

Matrix of Resources

A P P E N D I X

List of Acronyms

A/E Architectural and Engineering

BAS Building Automation System

CA Commissioning Agent

CFM Cubic Feet per Minute

CHWP Chilled Water Pump

CHWRT Chilled Water Return Temperature

CHWST Chilled Water Supply Temperature

CMMS Computerized Maintenance Management System

COV Change of Value

CPU Central Processing Unit

Cx Commissioning

DAT Discharge Air Temperature

DB Dry-Bulb Temperature

DDC Direct Digital Control

dP Differential Pressure

dT Differential Temperature

DX Direct Expansion

GPM Gallons per Minute

EMCS Energy Management Control System

EMS Energy Management System

HVAC Heating, Ventilating, and Air-Conditioning

HWST Hot Water Supply Temperature

IAQ Indoor Air Quality

LIT Lead Installing Technician

LP Lead Programmer

MAT Mixed Air Temperature

O&M Operations and Maintenance

OSAT Outside Air Temperature

PF Power Factor

PM Preventive Maintenance

RAT Return Air Temperature

RH Relative Humidity

RTU Rooftop Unit

SAT Supply Air Temperature

TAB Testing, Adjusting, and Balancing

TU Terminal Unit

VAV Variable Air Volume

VFD Variable Frequency Drive

WB Wet-Bulb Temperature

C-2

APPENDIX C

Bibliography

American Institute of Architects, “MasterSpec Section 15970: HVAC Controls,” 1994

American Institute of Architects, “MasterSpec Section 15975: Control Systems Equipment,” 1994

American Society of Heating, Refrigeration, and Air-conditioning Engineers, “Automatic Control,”“Building Operating Dynamics and Strategies,” “Building Commissioning,” ASHRAE Applications, 1995

American Society of Heating, Refrigeration, and Air-conditioning Engineers, Guideline 1-1996, The HVACCommissioning Process, 1996

American Society of Heating, Refrigeration, and Air-conditioning Engineers, “Optimal Control Strategies,”collected from ASHRAE Winter Meeting, 1993

Anderson, R., “Gems to Look for in EMS,” Heating, Piping, and Air Conditioning, November 1991

Brambley and Lin, “Use of Energy Management Systems for Remote Monitoring and Testing of BuildingPerformance,” ASHRAE Transactions, 1987

British Columbia Buildings Corporation, BCBC Comfort Control System Manual, download athttp://highrise.bcbc.gov.bc.ca/ccs

Carson and DiGiandomenico, “Selecting a BAS: Balancing Price, Features, and Support,” BuildingOperating Management, March 1991

Cratty and Williams, “Energy Management Control Systems,” from Energy Management Handbook,The Fairmont Press, 1992

Cumali, Z., “Global Optimization of HVAC System Operations in Real Time,” ASHRAE Transactions, 1988

DeLuga and Johnson, “Security Joining Building Automation,” Engineered Systems, June 1997

Grimm and Rosaler, Handbook of HVAC Design, McGraw Hill, 1990

Gupton, G., HVAC Controls: Operation and Maintenance, The Fairmont Press, 1996

Gustavson, D., “How to (Re)Invest in EMS… and Live to Tell About It,” Energy & Environmental Man-agement, Spring 1995

Hartman, T., “Dynamic Control: a New Approach,” Heating, Piping, and Air Conditioning,April 1988

Hartman, T., “Global Optimization Strategies for High-Performance Controls,” ASHRAETransactions, 1995

Heinemeier et al, “The Use of Energy Management and Control Systems for Retrofit Performance Moni-toring in the LoanSTAR Program,” Lawrence Berkeley Laboratory, 1992

Heinz and Casault, The Building Commissioning Handbook, APPA: The Association of Higher EducationFacilities Officers, 1996

Koran, W., “One Adventure in Using an EMS for Commissioning,” Proceedings of the First NationalConference on Building Commissioning, 1993

McGowan, J., Direct Digital Controls: a Guide to Building Automation, The Fairmont Press, 1995

Monger, S., HVAC Systems: Operation, Maintenance, and Optimization, Prentice Hall, 1992

National Electrical Contractors Association and Edison Electric Institute, Energy for the Year 2000:a Total Energy Management Handbook, 1997

C-3

ACRONYMS, BIBLIOGRAPHY, MATRIX

Norford et al, “Energy Management Systems as Diagnostic Tools for Building Managers and EnergyAuditors,” ASHRAE Transactions, 1987

Owens, G., “The Proper Selection, Care, and Feeding of a Large Centralized Energy ManagementSystem,” Energy Engineering, 1992

Ponds, M., “NERTs: Non-Energy Related Tasks,” Energy & Environmental Management,Summer 1995

Portland Energy Conservation Inc. (PECI) and U.S. Department of Energy, Model CommissioningPlan and Guide Specifications, 1997

Sabeff, P., “EMS as a Commissioning Tool,” Proceedings of the Second National Conference onBuilding Commissioning, 1994

State of Tennessee, “Energy Management Control System Specifications,” 1992

Thumann, A., Optimizing HVAC Systems, The Fairmont Press, 1988

C-4

APPENDIX C

AUTHOR TITLE

ASHRAE Automatic ControlApplications

ASHRAE Building CommissioningApplications

ASHRAE Building Operating DynamicsApplications and Strategies

ASHRAE Guideline 1-1996, The HVAC Cxg Process

ASHRAE Optimal Control Strategies

BCBC BCBC Comfort ControlSystem Design Manual

Cratty and Williams Energy Management Control Systems

Grimm and Rosaler Handbook of HVAC Design

Gupton, G. HVAC Controls: Operation &Maintenance

Heinz and Casault The Building Commissioning Handbook

McGowan, J. Direct Digital Control: a Guide toBuilding Automation

Monger, S. HVAC Systems: Operation, Maintenance,and Optimization

NECA and EEI Energy for the Year 2000: a TotalEnergy Management Handbook

Portland Energy Model Plan and Guide SpecificationsConservation Inc.(PECI)/U.S. Dept. ofEnergy

Thumann, A. Optimizing HVAC Systems

• •

•

•

•

•

•

• • •

• •

• • •

•

• • •

•

•

• •

• •

Matrix ofResources

Evalu

atio

n

Spec

ific

atio

ns

Co

mm

issio

nin

g

Ser

vic

eC

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tr

ac

ts

Optim

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Dia

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ostic

s

No

n-E

ner

gy

Applic

atio

ns

1 2 3 4 5 6 7

Actuators, 2-6Air-side

Economizing, see EconomizingHeat Recovery, 5-23

Alarms, 5-4Nuisance Alarms, 5-5Specifications for, 2-7

As-Built Drawings, 2-9Assessment, see EvaluationAuto-Diagnostics, 6-6

BACnet, see InteroperabilityBoiler System

Control, 5-22Lockout, 5-21

Building Space Pressure Control, 5-22

Calendar Scheduling, see SchedulingCalibration, 3-8, 5-10Carbon Dioxide Monitoring, see MonitoringCard Key Access, 7-3Chilled Water

Secondary Loop Pressure Reset, 5-21Supply Temperature Reset, 5-20

Chiller System, 5-22Cold Deck Reset, 5-19Commissioning, 3-1

Authority, 3-5Facilitation, 3-4Management, 3-9Plan, 3-7Specifications for, 2-9, 3-4, 3-5, A-5

Communications, Off-site, 2-6Completion Milestones, 2-9Computer and Monitor, 2-4Condenser Water Temperature Reset, 5-20

Dampers, 2-6Daily Scheduling, see SchedulingDaylight Dimming, 5-23Deadband, 5-4, 6-8Demand Limiting, 5-24Design Intent, 3-5Design Review, 3-4Diagnostics, 6-1Discharge Air Reset, 5-18Distributed Panels, 2-5Documentation, 5-8Downloading Data, 6-5Dual Setpoint Control, 5-4DX Compressor Cooling, 5-22

Economizing, Air-side, 5-18Energy Management Systems

Commissioning of, see CommissioningEvaluation of, see EvaluationManufacturers as Service Contract Providers, 4-1Printers and Portables, 2-5Procurement Methods for, 2-1, 3-3Proposals, Selecting, see ProposalsSpecifications for, see Specifications

Energy-Conserving Control Strategies, 5-14Evaluation, 1-1Evaluation Matrix, see ProposalsException Scheduling, see SchedulingExhaust Fans, 5-17

Filter Control, 7-2Flow Sensing Methods, 5-17Full-Maintenance Service Agreement, 4-2Full-Service Agreement, 4-3Functional Testing, 3-8, 5-11

Cautions when Testing, 5-11Initiating a System Response for, 5-12

Functionality, 2-11

Gages, 2-6

Hardware, 2-11Expandability, 2-3Initial Checkout, 3-7Interfacing, 2-4

Heat Recovery, see Air-Side Heat RecoveryHeating Water

Secondary Loop Pressure Reset, 5-21Temperature Reset, 5-19

Hot Deck Reset, 5-19

Indoor Air Quality, 5-23, 7-6Industrial Applications, 7-4Injection Fans, 5-17Interoperability, 2-4

Lighting ControlSweep, 5-23Zonal, 5-23

Load Shedding, 5-24Lockouts, 5-21Long-Term Purchasing Agreement, 4-4

Maintenance Control, 7-1Malfunctions, 6-7Manual Testing, 6-9Mechanical Contractors as Service Contract Providers, 4-1Mixed Air Temperature Reset, 5-19Monitoring, 5-5

Carbon Dioxide, 5-17Energy Monitoring, 5-24

Morning Warm-up/Cool-down, 5-16

National Maintenance Service Firms, 4-1Network Criteria, 2-5Night Setup/Setback, 5-15Night Ventilation Purge, 5-18Noise Control, 7-5Non-Energy Applications, 7-1

Occupancy Sensors, 5-23For Ventilation Control, 5-17

Open/Flexible Service Agreement, 4-3Operational Checkout, 3-8

INDEX

Operations and Maintenance, 3-4Documentation, 2-9, 3-9

Optimization, 5-1Essential Skills for, 5-8Examples of, 5-25Prerequisites for, 5-7Strategies for, see Strategies

Optimum Start, 5-15Sequential Startup of Equipment, 5-24

Optimum Stop, 5-16“Orphan” System, 1-1, 1-5Outside Air Damper Compensation Routines, see VentilationOverride Control, 5-15

Performance Contracts, 5-25Pneumatic Systems, 1-4Pressure Control, see Building Space Pressure ControlPreventive Maintenance Service Agreement, 4-3Proposals

Cost Considerations of, 2-12, 2-13Evaluation Matrix for, 2-14Selecting, 2-10

Procurement, see Energy Management SystemsProject Manager, 3-6

Remote Operation, 7-2Replacements, 1-5Reports, 2-7Resets, 5-18

Reset Interactions, 5-21Resistance Heat Lockout, 5-22Retail Applications, 7-5Retrofits, see UpgradesRun-Time Tracking, 7-2

Sampling Rates, 6-2Safeties, 5-5Scheduling, 5-2, 5-14

Calendar, 5-2Daily, 5-2Exception, 5-3Holiday, 5-14Zonal, 5-15

Security, 7-3Specifications for, 2-7

SensorsCalibration of, see CalibrationSpecifications for, 2-5

Sequences of Operation, 5-9Specifications for, 2-8

Service Contracts, 4-1Providers, 4-1Selection of, 4-5Types, 4-2

Setpoints, 5-3Basic Setpoints, 5-4Space Temperature, 5-3

Sewer Fee Control, 7-2Simultaneous Heating/Cooling Control, 5-22

Software, 2-6Initial Checkout, 3-7Programming Access, 2-7User Interface and Graphics, 2-6

Software (Remote) Monitoring Agreement, 4-3Space Temperature Setpoints, see SetpointsSpecifications, 2-1

Development and Review, 2-2Guide Specifications, 2-1Performance Specifications, 2-2Proprietary Specifications, 2-2Sample, A-1Submittals, 2-9

Spreadsheets, 6-7, B-1Strategies

Commissioning of, 3-4Current Control Strategies, 5-10List of, 5-14Specifications for, 2-8

Supply Air Reset, 5-18Supply Air Volume Compensation Routines, see Ventilation

Technical Support Agreement, 4-4Tenant Billing, 5-15Test Ports, 2-6Totalization, 6-6Training, 2-9, 3-4, 3-9Trending, 5-5, 6-1

Analysis, 6-7Points for, 5-6

Specifications for, 2-7Types, 6-2

Upgrades, 1-4Special Considerations for, 2-10

ValvesCalibration of, see CalibrationSpecifications for, 2-6

Variable Air VolumeFan Duct Pressure and Flow, 5-19

Vendor, 3-6Facility References of, 2-13Qualifications, 2-8, 2-10, 2-13Support, 2-10, 2-13

Ventilation Control, 5-16Supply Air Volume/Outside Air Damper Compensation, 5-17

Viewing Data, 6-6

Warranty, 2-10Water Treatment, 7-2